In this task, you need to reverse all words of a given length in the sentence. The number of letters in a word determine its length. For example, the length of the word "apple" is 5.

Sentence: 'a plate of two tacos with fillings and a side of orange slices'. Reverse all words of length '6' in the given sentence.
a plate of two tacos with fillings and a side of egnaro secils