How can I encounter players to play my game Crysis 2 online? On the XBOX 360 I cannot encounter anybody to play.

I regret to inform you that the xbox live community is practically dead in every gametype except for Team Instant Action and Instant Action. If you wait in a lobby in one of those gametypes long enough, you should find players or get transferred to an active lobby. Unfortunately you probably won't be able to find players in the other gametypes unless you bring a full party to them yourself.