I have a audi 90, my radiator is bad. But I have also an AFC engine from A6.
My question is will the radiator from A6 V6 fit into my 90 V6

You have to do a little bit of research yourself, it's not rocket science. Check the part numbers, Audi and VW often have the numbers cast or stamped on the parts. You can also look on rockauto.com and see if they have the same part numbers for both models.

thanks man, unfortunatly the parts are different in size and in tranny hook up.