Assuming it's the same chickens in both photos, I'd guess the one on left in both is the roo. The comb and wattles look more pronounced, the tail looks a bit showier and I MAY see some saddle feathering. Of course, could be a hen with a bigger comb. If you could manage to get up-close shots, I'm sure someone could tell for sure.
I think they're both young mixed breed roosters. One appears to have a straight comb, one looks to have a rose? comb, and the coloring just looks mixed to me.