A method and system for operating a multi-Subscriber Identity Module (SIM) mobile device are provided. The method includes determining whether at least one Registered Public Land Mobile Network (RPLMN) among a first RPLMN of a first SIM and a second RPLMN of a second SIM of the multi-SIM mobile device is unavailable to the multi-SIM mobile device when the multi-SIM mobile device triggers a Public Land Mobile Network (PLMN) search, identifying a common PLMN, from a first PLMN set associated with the first SIM and a second PLMN set associated with the second SIM, in response to determining that the at least one RPLMN among the first RPLMN and the second RPLMN is unavailable, and camping on the common PLMN by the first SIM and the second SIM after acquiring camping information of the common PLMN.