The RAND function returns numbers from the interval [0,1), and if you need to generate numbers from another interval, you should use the following formula: =RAND() * (bâa) + a. This will return random numbers from the interval [a,b) - greater than or equal to a, and less than b.
At the time, 5.4 was made available as a beta release alongside the stable 5.3.4 release. Now that 5.4 has become the latest stable Unity release, it seems the company intends to keep the program going a beta version of Unity 5.5 is slated to debut in the near future. source.
If you download Unity 3D for the first time, you will get a trial version of Unity Pro including iOS and Android trials for 30 days with possibility to build your game app.