A mobile ad-hoc network is multi hop wireless network that consists of mobile nodes that communicate with each other. The nodes communicate with each other by means of the air as the medium. Each node in the network moves freely and so the topology changes continuously. One of the challenges of MANET is to design robust routing algorithms so that they adapt to frequently changing network topology. Simulation of variety of routing protocols has been carried out extensively. In this paper, we will study the performance of two types of On demand routing protocols-Ad-hoc On-demand Distance Vector (AODV) and Ad-hoc On- demand Multi path Distance Vector (AOMDV).