user18675: Firstly I got 1018 rating last year. Then next tournament deducted 25 and my FIDE rating became zero. 

Then I faced next tournament opponent 03 players 1352, 1255 and 1174 respectively. All 03 games I lost.
Then I faced next tournament opponent 03 players 1288, 1315 and 1153 respectively. I won 1315 rated game and other 02 lost.
Then I faced next tournament opponent 02 players 1227 and 1334 respectively. I won 0.5 with draw 1334 rated player and other one lost.

Then I already got 1.5 points, but still my FIDE rating is showing 0. I want to know how many games I need to play and win to again take my FIDE rating.

user4418: 
Then I already got 1.5 points, but still my fide rating is showing 0.
  I want to know how many games need to play and win to again take my
  fide rating.

According to the FIDE Rating Regulations

7.2 Players who are not to be included on the list:
  7.21 Players whose ratings drop below 1000 are listed on the next list as 'delisted'. Thereafter they are treated in the same manner as any
  other unrated player.

Since your rating went below 1000 you count as a new player for rating purposes and this section applies:

7.14 A rating for a player new to the list shall be published only if it meets the following criteria:
7.14a If based on results obtained under 6.3, a minimum of 5 games.
7.14b If based on results obtained under 6.4, a minimum of 5 games played against rated opponents.
7.14c The condition of a minimum of 5 games need not be met in one tournament. Results from other tournaments played within consecutive
  rating periods of not more than 26 months are pooled to obtain the
  initial rating.
7.14d The rating is at least 1000.
7.14e The rating is calculated using all his results as if they were played in one tournament (it is not published until he has played at
  least 5 games) by using all the rating data available.

Bottom line: you need to play well enough to bring your rating back to 1000 or above to have your rating reinstated.

user4418: 
please check Ekanayake E M Anindu Rehan Fide ID is 29909279

OK, so this is your playing record -
2017-10
1754    0
1155    0
1371    0   
2017-11
1112    0   
2018-04 (1018)
1286    0
1079    0
1018    1
1318    0
1067    1
1090    0   
2018-05 (1018 - 25.2 -> 0)
1418    0
1332    0
1221    0
1292    0   
2018-10
1352    0
1255    0
1174    0   
2018-11
1288    0
1315    1
1153    0   
2019-02
1227    0
1334    0.5   
Let's go back and check the FIDE rating regulations.

6.1 If an unrated player scores zero in his first tournament, his score and that of his opponents against him are disregarded. 
  Otherwise if an unrated player has played rated games, then this
  result is included in computing his overall rating.

In your first two tournaments you scored zero points so these are not used in any rating calculations.
You got your first rating of 1018 in the April 2018 list after a tournament in the previous month. Let's see how the calculation works. First the relevant parts of rating regulations:

8.2 Determining the Rating 'Ru' in a given event of a previously unrated player.
  8.21 If an unrated player scores zero in his first event his score is disregarded.    First determine the average rating of his competition
  'Rc'.
  (a) In a Swiss or Team tournament: this is simply the average
  rating of his opponents.    ...
  8.24 If he scores less than 50% in a Swiss or team tournament:  Ru = Ra + dp

2018-04 (1018)
1286    0
1079    0
1018    1
1318    0
1067    1
1090    0
Sum of opponents' ratings = 6858
Average of opponents' ratings = Rc = 6858 / 6 = 1143
You scored 2/6 which is 33%. Hence:
Fractional score = p = .33,
Then I look up in table 8.1a from the rating regulations to find 'dp'
dp = -125 so new rating = 1143 - 125 = 1018   
Now if we repeat the calculation for what your current rating would be we again throw away the first two tournaments (2017-10 and 2017-11) and use all the tournaments since then.
We get:
Total sum of opponents' ratings = 6858 + 5263 + 3781 + 3756 + 2561 = 22219
Total games = 18
Rc = 22219 / 18 = 1234.39
p = 3.5/18 x 100 = 19.4%
dp = -251 (looking up in table 8.1a for p=0.19)
So new rating = 1234.39 - 251 = 983.39   
This is less than 1000 so you are recorded as unrated.
If your fractional score had been 0.21 (i.e. you scored 4 / 18) then dp according to table 8.1a would be -230.4 and you would have had a rating of 1004.
So, basically you fell short by one draw. If you continue winning one game in three against similar opposition then you should make it.

18675: <p>Firstly I got 1018 rating last year. Then next tournament deducted 25 and my FIDE rating became zero. </p>

<ol>
<li>Then I faced next tournament opponent 03 players 1352, 1255 and 1174 respectively. All 03 games I lost.</li>
<li>Then I faced next tournament opponent 03 players 1288, 1315 and 1153 respectively. I won 1315 rated game and other 02 lost.</li>
<li>Then I faced next tournament opponent 02 players 1227 and 1334 respectively. I won 0.5 with draw 1334 rated player and other one lost.</li>
</ol>

<p>Then I already got 1.5 points, but still my FIDE rating is showing 0. I want to know how many games I need to play and win to again take my FIDE rating.</p>
 4418: <blockquote>
  <p>Then I already got 1.5 points, but still my fide rating is showing 0.
  I want to know how many games need to play and win to again take my
  fide rating.</p>
</blockquote>

<p>According to the <a href="https://www.fide.com/fide/handbook.html?id=197&amp;view=article" rel="nofollow noreferrer">FIDE Rating Regulations</a></p>

<blockquote>
  <p>7.2 Players who are not to be included on the list:<br>
  7.21 Players whose ratings drop below 1000 are listed on the next list as 'delisted'. Thereafter they are treated in the same manner as any
  other unrated player.</p>
</blockquote>

<p>Since your rating went below 1000 you count as a new player for rating purposes and this section applies:</p>

<blockquote>
  <p>7.14 A rating for a player new to the list shall be published only if it meets the following criteria:</p>
  
  <p>7.14a If based on results obtained under 6.3, a minimum of 5 games.</p>
  
  <p>7.14b If based on results obtained under 6.4, a minimum of 5 games played against rated opponents.</p>
  
  <p>7.14c The condition of a minimum of 5 games need not be met in one tournament. <strong>Results from other tournaments played within consecutive
  rating periods of not more than 26 months are pooled to obtain the
  initial rating</strong>.</p>
  
  <p>7.14d The rating is at least 1000.</p>
  
  <p>7.14e <strong>The rating is calculated using all his results as if they were played in one tournament</strong> (it is not published until he has played at
  least 5 games) by using all the rating data available.</p>
</blockquote>

<p>Bottom line: you need to play well enough to bring your rating back to 1000 or above to have your rating reinstated.</p>
 4418: <blockquote>
  <p>please check Ekanayake E M Anindu Rehan Fide ID is 29909279</p>
</blockquote>

<p>OK, so this is your playing record -</p>

<p><strong>2017-10</strong><br>
1754    0<br>
1155    0<br>
1371    0   </p>

<p><strong>2017-11</strong><br>
1112    0   </p>

<p><strong>2018-04</strong> (1018)<br>
1286    0<br>
1079    0<br>
1018    1<br>
1318    0<br>
1067    1<br>
1090    0   </p>

<p><strong>2018-05</strong> (1018 - 25.2 -> 0)<br>
1418    0<br>
1332    0<br>
1221    0<br>
1292    0   </p>

<p><strong>2018-10</strong><br>
1352    0<br>
1255    0<br>
1174    0   </p>

<p><strong>2018-11</strong><br>
1288    0<br>
1315    1<br>
1153    0   </p>

<p><strong>2019-02</strong><br>
1227    0<br>
1334    0.5   </p>

<p>Let's go back and check the <a href="https://www.fide.com/fide/handbook.html?id=197&amp;view=article" rel="nofollow noreferrer">FIDE rating regulations</a>.</p>

<blockquote>
  <p>6.1 If an unrated player scores zero in his first tournament, his score and that of his opponents against him are disregarded. 
  Otherwise if an unrated player has played rated games, then this
  result is included in computing his overall rating.</p>
</blockquote>

<p>In your first two tournaments you scored zero points so these are not used in any rating calculations.</p>

<p>You got your first rating of 1018 in the April 2018 list after a tournament in the previous month. Let's see how the calculation works. First the relevant parts of rating regulations:</p>

<blockquote>
  <p>8.2 Determining the Rating 'Ru' in a given event of a previously unrated player.<br>
  8.21 If an unrated player scores zero in his first event his score is disregarded.    First determine the average rating of his competition
  'Rc'.<br>
  (a) In a Swiss or Team tournament: this is simply the average
  rating of his opponents.    ...<br>
  8.24 If he scores less than 50% in a Swiss or team tournament:  Ru = Ra + dp</p>
</blockquote>

<p><strong>2018-04</strong> (1018)<br>
1286    0<br>
1079    0<br>
1018    1<br>
1318    0<br>
1067    1<br>
1090    0<br>
Sum of opponents' ratings = 6858<br>
Average of opponents' ratings = Rc = 6858 / 6 = 1143<br>
You scored 2/6 which is 33%. Hence:<br>
Fractional score = p = .33,<br>
Then I look up in table 8.1a from the rating regulations to find 'dp'<br>
dp = -125 so new rating = 1143 - 125 = 1018   </p>

<p>Now if we repeat the calculation for what your current rating would be we again throw away the first two tournaments (2017-10 and 2017-11) and use all the tournaments since then.</p>

<p>We get:<br>
Total sum of opponents' ratings = 6858 + 5263 + 3781 + 3756 + 2561 = 22219<br>
Total games = 18<br>
Rc = 22219 / 18 = 1234.39<br>
p = 3.5/18 x 100 = 19.4%<br>
dp = -251 (looking up in table 8.1a for p=0.19)<br>
So new rating = 1234.39 - 251 = 983.39   </p>

<p>This is less than 1000 so you are recorded as unrated.</p>

<p>If your fractional score had been 0.21 (i.e. you scored 4 / 18) then dp according to table 8.1a would be -230.4 and you would have had a rating of 1004.</p>

<p>So, basically you fell short by one draw. If you continue winning one game in three against similar opposition then you should make it.</p>
