I'd guess roo, too. Look for long sweeping feathers near his tail- those are saddle feathers. Also pointier neck (hackle) feathers compared to a hen's more rounded-ending feathers.
I bought one like it. The seller told me it's a hen. However, after about 4 wks it turned out to be a rooster. It ended up as chicken curry for my dinner
As for this one here. I'd say it's 100% rooster (looks like mine)!!!