New cat I need help

Ok so I have a 5 year old and a 3 year old both male cats wonderful both get along until today my sister no longer could keep her cat which was isolated a lot that's why I was trying to help her got her 5 year old female home she came out of the cage I was following her and my oldest male was hissing and a little growling well Tried to bring my other cat to her she bit me my oldest chased her I finally got them all three separated now my oldest male does not get along with my other male cat what can I do to keep them all

Have they all been fixed?

Yes

When you brought home the new cat, did you isolate her and them and do scent swapping and meetings through a baby gate? Cats really need slow introductions.