The disclosure relates to a 5th generation (5G), pre-5G, or 6th generation (6G) communication system for supporting higher data rates after a fourth generation (4G) communication system such as long term evolution (LTE). A method of a mobility management entity in a wireless communication system includes receiving an attach request for a first network among at least two networks supported by the UE including first capability information including information related to a second network among the at least two networks is, transmitting an attach response indicating completion of attach of the first network to the UE, receiving, from the UE, a session establishment request for the first network after transmitting the attach response, and establishing a session for the first network of the UE through a session management entity supporting mobility between the first network and the second network.