Objective: Wireless Sensor Networks (WSN) with IP compatibility consists of nodes that has limited resources such as reduced processing and memory capabilities, less battery life and reduced transmission range. The aim of this research work is to evaluate and implement such a routing scheme, which leads to efficient utilization of nodes and network scarce resources. Methodology: RPL (Routing Protocol for Low Power Lossy Network), a standard routing protocol for IP enabled WSN is considered as an efficient protocol for such network. In this research work, the performance of RPL will be analysed based on different Objective Function (i.e. Expected Transmission Count & Objective Function Zero) in various radio models (Unit Disc Graph Model - Distance Loss, Unit Disc Graph Model - Constant Loss, Multi-Path Ray-Tracer Medium) and scaled networks which makes this implementation unique and the results obtained are compatible to real time scenario. To analyse the performance of RPL with different Objective Function, various performance parameters are calculated e.g. Packet Delivery Ratio, Control Traffic Overhead, Power Consumed, Network ETX. Each of these performance parameters are compared for both the Objective Functions, to analyse which Objective Function of RPL has more efficient performance in various radio models and scaled networks. Findings: From the simulation results analysed, it is proved in this paper that the performance of ETX is better in comparison to OF0 for all the radio models and the scaled networks.