It would be a fantastic idea to have a lunar positioning system similar to the GPS (global positioning system) available in the earth.
This could be a fundamental advantage to India and help other nations in their quest to understand moon and the later utilization.
A much simpler system than the GPS could contain several smaller satellites which may be launched as a bigger satellite (with several small satellites forming clusters) from the earth but reorients itself over the moon to provide a seamless lunar positioning system.