If you're referring to WW2 crimes, Serbs committed just as many. Ustasha and Chetniks were all the same type of ****, and one of the two were killed off at the end of WW2, guess which.

First, persons commit crimes, not entire peoples. I dont hold Croatian people responsible for what Ustaše did.
Second, put aside whaether two sides you mentioned were or were not same kind of feces, shortly they did not commited as many killings. But again lititation with numbers is wrong.