The various embodiments herein provide a method and system for operating a multi-subscriber identity module (SIM) mobile device. The method includes identifying a common suitable public land mobile network (PLMN) cell between a first radio frequency (RF) unit and a second RF unit of the mobile device. The first RF unit and the second RF unit of the mobile device are currently camped on different PLMN cells. Further, the method includes enforcing at least one of the first RF unit and the second RF unit to camp on said common suitable PLMN cell and disabling one of the first RF unit and the second RF unit when at least one of the first RF unit and the second RF unit camps on the common suitable PLMN cell.