The partition of the Indian sub-continent in 1947 had certain rules regarding the alliance of the various princely states, giving the leaders of these states the right to chose Pakistan, India, or, sometimes, independence. Although 77% Islamic, Kashmir chose India, much to the chagrin of Pakistan. Lots of little military activities took place and the UN was involved, and by 1956, the Muslim leader of Kashmir chose to ally once again with India.
A few years ago I saw a TV programme about the problem, at a border crossing, each evening, the two opposing commanding officers, in almost identical uniforms except colour, marched to their respective gates, saluted each other, glared at each other, locked their gates, and then went off to have dinner together, what is going on, I do hope they haven't given up breaking bread with each other, they were both probably good mates at Sandhurst.
When will Kashmir be free? Free from what, I don't think that they ever opted for independence.