How to tell if a male is neutered

Hello! I have a male rabbit that was given to me because the former owner couldn't take care of him. He is awesome, but I was wondering if there is any way to tell by looking if he has been fixed. I want to get another rabbit for him so he has company while I'm at work and found a male at a rabbit rescue that I really like. But I heard that if my rabbit isn't fixed he may be aggressive to another male and I don't want that.

How old is he? A male rabbit over about 3 months old would have quite obvious testicles.
Are you sure it is a boy? Mistakes on gender are quite common.

The best bet would be to get him checked out by a vet, and discus vaccination at the same time. I'm assuming he hasn't been vaccinated, or you would have a vaccination card and you could ring the surgery named on the card to find out his other history (eg neutering).

Bunnies like having a bunny friend, so it is a really good idea looking in rescues for another. Un-neutered rabbits can get very aggressive with each other - so bonding should be done when both have been neutered a few weeks previously and are less hormonal.

As above if.he.is older then 3months the testicles will be clear to see on the rabbit