Wireless Sensor Network (WSN) is an emerging technology that shows great promise for various futuristic applications both for mass public and military. A wireless sensor node consists of sensing, computing, communication, actuation, and power components. These sensing devices have the opportunity of collaboration amongst themselves to improve the target localization and tracking accuracies. Distributed data fusion architecture provides a collaborative tracking framework. Due to the present energy constraints of these small sensing and wireless communicating devices, a common trend is to put some of them into a dormant state. The problem of obtaining a minimum cost topology for a wireless sensor network given matrices specifying the cost of links between all pairs of nodes and the internodes requirements is considered. This paper discusses the optimizing strategy for routing and selecting optimum number of nodes using MENTOR algorithm. In this we find the path with minimum cost between numbers of nodes in the network. It is closely related to decision on what speed links to use and how to route traffic through the network.