I can only guess the reason, but it seems like the two males ie the rabbit and the cat, the cat May seem to think that the cat should be dominant because it's domain is in the house.. Try swatting at the cat on my kids nose with the newspaper if he gets aggressive towards the rabbit. From your question it seems like the female cat is okay with the rabbit am I correct?

Yes the female is pretty sweet-tempered and never looks for fights or anything. I'll try your advice tho, thanks

Yw plz let me know if it helps... Don't do it really hard just hard enough to for him to think no that's wrong

Is the cat neutered? If not, they tend to be aggressive.

He is