Yes, you need to keep them separated until they are both fixed. I’m not sure what your intentions were when you got them, but you need to keep them separated as they have reached sexual maturity at this age. Especially since you are not sure of their sex, they must stay separated. If given any opportunity they will mate and you will have a pregnant baby bunny on your hands- not healthy for her at all! Try and figure out the sex and get them spayed/neutered. Are you in the US? If so, we can help you locate a rabbit savvy vet near you, let me know if you would like the link for the list of U.S vets. Until then, please don’t allow them to be together because they will continue to fight. It’s not that they don’t like each other, it’s because now they are sexually mature and they feel threatened by one another. They each want to have the territory to themselves. It will be very dangerous if you put them together, as rabbits can fight to the death.
Also, how big is the opening between cage bars? If it is big enough for one to stick their nose out, it is dangerous to have the other one in the same room. One could bite/scratch the other from outside of the cage, and I’ve even heard of rabbits mating through cage bars. Is it possible to keep the cage in a separate room?