Yes, a cat would attack a rabbit under the right circumstances and if the individual cat concerned likes to attack rabbits.
It looks as if there are a lot of internet surfers (young people, I sense) who look after a cat and they want to adopt a rabbit (or vice versa) so they ask, on the internet, whether their cat would attack their rabbit.
There is absolutely no question that a domestic cat might attack a rabbit and eat it. It all depends upon the individual cat. A rabbit is definitely prey to a domestic cat. It is larger than average prey but prey nonetheless.
The domestic cat is an opportunistic hunter. They will attack and eat whatever they can. They usually hunt rodents, reptiles and birds.
Not all domestic cats will want to attack and eat a rabbit. So you are going to have to find out whether the cat that you wish to adopt or the cat that you have already adopted likes to attack rabbits before you get a rabbit. Or if you have a rabbit then once again you will have to try and find out whether your cat cat likes to hunt them. That may be impractical without hurting a rabbit if you think about it!
If you already have a rabbit and wish to adopt a domestic cat then it seems to me that the only way to find out whether he likes to attack rabbits is to adopt the cat and see whether he does it. If he does attack rabbits then you’ll have to keep them separate which is not ideal and the cat adoption would be somewhat of a failure. However, I don’t see an alternative way to proceed except, come to think about it, there is one good alternative.
If you adopt a young kitten and a young rabbit and you put them together and raise them together, they will end up being best buddies and the cat will never attack the rabbit. Or if you adopt a young rabbit and it suckles on the breast of a cat mother who is nursing her young then once again the kittens who were raised with the rabbit will be best friends and there will be no chance of the adult cats attacking the rabbit.
I am almost certain that you have read the many stories about young puppies, squirrels, and other species of animal being raised by mother cats. They all end up as best friends.