It really depends on the individual animals but cats and rabbits can absolutely be friendly, or at least cohabitate nicely. The cat, depending on it’s personality, may need a lot of training with a spray bottle if it thinks the rabbits are toys or snacks. I have one small breed rabbit and one cat who likes to bother him occasionally. The general rule in our house is that cats are never allowed to swat at rabbits, rabbits are always allowed to defend themselves, and the crazy cat in general is encouraged to simply avoid the rabbits.
That said, my first bun was desperately lonely the first 3 months I had him and made friends with another of my cats. They don’t hang out anymore now that he has a bunny friend, but the cat was very good with him. We have a 3rd cat who is friendly with them. She head butts them and plays a chasing game with them where she chases them across the room then they turn and chase her back. All 3 of my rabbits enjoy this game (I know it seems crazy) but she’s their buddy and she has never hurt them. So it’s really all down to watching them very closely at first, training the cat, then seeing what type of relationship the rabbits want to have and encouraging the cat to live within those boundaries.