In recent years ad hoc networks have opened a new dimension in wireless networks with a large number of mobile nodes. It allows wireless nodes to communicate with each other in the absence of centralized support. Ad hoc networks do not follow any fixed infrastructure because of the mobility of nodes and multi-path propagation. Due to the dynamic topology and routing overhead, selection of routing protocol in Mobile Ad-hoc Network (MANET) is a great challenge. A design issue for an efficient and effective routing protocol is to achieve optimum value of performance parameters under network scenarios. There are various protocols available for MANET. In the past, tremendous work has been done on comparison and evaluation of routing algorithms for MANET using NS2 (Network Simulator 2). This project involves study on the Proactive and Reactive routing protocols like OLSR (Optimized Link State Routing Protocol), DSDV (Distance Sequenced Distance Vector), AODV (Ad-Hoc On Demand Distance Vector Routing) and comparison between these routing protocols on the basis of performance metrics (throughput, packet delivery ratio, packet dropped, jitter, end to end delay etc.) with the help of NS3 simulator.