The routing protocol for low power and lossy network (RPL) has tremendous scope in IoT, due to the fact that it can be customised as per network's domain requirement by altering objective function (OF). Many studies have proven that the careful crafting of OF with different metrics improve the quality of route identified by RPL. As the complexity of OF increases due to different metric combinations, the performance of RPL will start to deteriorate. We divide OF into a two-stage process to solve this problem. In the first stage we keep a simple OF that considers ETX and path delay and rank parents as per RPL specification. A fixed number of best ranked parents from the first stage OF are considered for further processing in the second stage OF. Fuzzy-based second stage OF considers mobility history, queue availability and remaining energy of the parents to select the preferred route. Second stage OF is run only on limited number of parents which improves performance of RPL. Performance evaluation shows that our two-stage objective function (TS-OF) reduces packet loss by 28% and energy consumption by 34% compared to the state of the art RPL objective function.