Question

i and you are class fellows.is it correct?

Answer 1

You and i are the class fellow

Answer 2

This is a common usage in terms of the usage of the English language.

It is a common form of redundancy that can be seen in common verbal and even written usages.

Since fellow and classmate perform the same set of function, there is no use in making the word class fellows again.

However, class mate is not used here, so class fellows can be a better option.