The Network-on-Chip (NoC) approach for designing System-on-Chip (SoC) is currently emerging as an advanced concept for overcoming the scalability and efficiency problems of traditional on-chip interconnection schemes, such as shared buses and point-to-point links. NoC design draws on concepts from computer networks to interconnect Intellectual Property (IP) cores in a structured and scalable way, promoting design re-use. This paper presents the design and evaluation of a parameterizable NoC router for FPGAs. The importance of low area overhead for NoC components is crucial in FPGAs, which have fixed logic and routing resources. We achieve a low area router design through optimizations in switching fabric and dual purpose buffer/connection signals. We use a store and forward flow control with input and output buffering. We propose a component library to increase re-use and allow tailoring of parameters for application specific NoC's of various sizes. Our router supports the mesh topology which is well known for its scalability and simple XY routing algorithm. We introduce IP-core-to-router mapping strategies for multi-local port routers that provide ample opportunity to optimize the NoC for application specific data traffic. A set of experiments were conducted to explore the design space of the proposed NoC router using different values of key router parameters: channel width (flit size), arbitration scheme and IP-core-to-router mapping strategy. Area and latency results from the experiments are presented and analyzed. These results will be useful to designers who want to utilize NoC for implementing large multi-core systems in Field Programmable Systems on Chip (FPSoC).