In WSN assisted IoT networks, the devices have to search the path up to the IoT hub for data transmission. Although the device’s hardware capabilities are increasing day by day, the device’s battery capacity is not increasing at the same rate. IoT devices have limited-power batteries that are not rechargeable. It is also challenging to replace their battery while the devices are in use. Moreover, we need advanced power-saving schemes to make these IoT technologies more adaptable. Due to the energy constraints and limited memory capacity of these IoT devices, we require more energy-efficient routing protocols to route data to the IoT hub. This paper has surveyed the most recent state-of-the-art routing protocol and highlighted their limits and path for future research.