As far as I can tell, it looks like a Rhode Island x Cochin. Looks like an all right cockerel, too. Cochins are generally very calm and docile, even cockerels, so hopefully he'll inherit those traits! Out of curiosity, what variety was the Cochin, or don't you know?
I have heard that people LOVE their Cochin roosters and I have also heard that a downside to Rhode Island Reds are that the roosters are very aggressive. I guess you will have to wait and see.