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 performed by a mobility management entity in a wireless communication system includes receiving an attach request for first network among at least two networks supported by UE including first capability information including information related to second network among at least two networks is, transmitting an attach response indicating completion of attach of first network to UE, receiving, from UE, session establishment request for first network after transmitting attach response, and establishing a session for first network of UE through a session management entity supporting mobility between first network and second network.