That doesn't always mean it's a roo some pullets have big combs. My Starlight Green Eggers had big combs and are hens. You really can't know if it's a roo or a hen quite yet. We were positive that we had three roos and only ended up with the Turken being male.
I know that this is an old post but if you are still on here and still have your roo. Could you post a pic of it with its collar on? I'm in the same predicament as you were in. I'm in an area where Roos aren't allowed and would like to try an anti-crow collar before I need to get rid of him. Thanks.
1 Turken, 2 Starlight Green Eggers, 3 Dominiques around 4 weeks of age. I posted these pics on a couple of Facebook Groups, as well. My husband and I are not allowed roo's where we live.