Embodiments herein provide a method for maintaining service continuity by a User Equipment (UE) in a wireless communication system. The method includes transmitting a registration request message or a tracking area update (TAU) message to a management entity of a first radio access technology (RAT) network, when the UE is registered in the first RAT network and a second RAT network; receiving, from the management entity, a registration reject message or a TAU reject message; and transmitting, to the management entity, a registration message for initial registration or an attach request message including a registration status information of the UE of the second RAT network.