Unfortunately baby rabbits cannot bond (but they will get along for a while), and once they hit puberty, they are likely to fight, as yours have.
You will need to neuter/spay both of them before you attempt to re-bond. You did the right thing by separating them!
For now, keep them separated, and get the other one neutered. Males need about 6 weeks for their hormones to settle. Females need longer… I can’t remember the exact amount, but I believe it’s 2-3 months.
How bad was the fight? Was either bun injured at all? If so, you’ll want to take a break from having them see each other at all, to let their hurt feelings and grudges heal.
If they fight wasn’t too bad (you stopped it before anyone was hurt), then you can start “pre-bonding”, which means swapping their cages so they lose track of territories and get used to the other bun’s scent being in their area.
After 1 month of pre-bonding, you can start sessions in neutral space again. Some people find small spaces work well, others like large spaces. I think with scared nervous bunnies large spaces are better, as they can get away from the other bunny if they want to, rather than feel like they have to fight to defend themselves.
During all of this time, make sure they can’t access each other through cage bars or fencing. Sight and smell is good, but no physical contact until you do supervised bonding sessions. This is very important! Every time they “jump the fence” and fight, you take several steps backward to them being bonded and risk someone being seriously injured. So please modify your set up so this isn’t possible.
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The answers provided in this discussion are for general guideline purposes only. The information is not intended to diagnose or treat your pet. Seek the advice of your veterinarian or a qualified behaviorist.