Honestly, they will probably all try to kill each other.
Do you want to breed them, or not? I can't tell from your phrasing.
If you don't want chicken wars, you should keep them separate until they get used to each other, then introduce them for short periods under supervision. If they do well with each other, then you might just leave them together.
But if you have two roos that didn't grow up together and don't currently live together in harmony, you could have a bloody mess on your hands.
Once I made the mistake of only restraining one of my new roos, thinking the other couldn't get to him in the cage. I was wrong.
Good luck!
-Sara