C'mon, stop bringing Pakistan into this. India has mismanaged Kashmir so badly that the majority of the population wants to leave India -- and not to join Pakistan, mind you, but to be independent.
So a resourceless Pakistan miraculously recovered from the bloody partition in mere three months to not only plan an insurgency, but also had the resources to execute it. Go Pakistan then? right?
First condition of plebiscite is withdrawal of Pakistani forces from occupied territories, 73 years and still waiting. India doesn't allow UN observers because they have outlived their utility, as LoC has been codified between Pakistan and India through Simla Agreement in 1971.