In 4G-domain multi home mobile host (MH) will have access to different wireless networks. In this 4G wireless networks real time applications are initiated to support services like VOIP, videoconference. These applications use RTP over UDP. These protocols are unresponsive to congestion events. Our proposed congestion management scheme minimizes congestion level in 4G domains using coalition game. Its main objective is to decide target networks for handoff with minimum congestion level. Our mechanism is based on the coalition game formation. It aims at maximizing the utilization of the resources available and meeting QoS requirement of users as much as possible. This will reduce congestion level with vertical handoff initiation.