The first Indian response is unlikely to be (as I say below) a desire to merge with Pak. Average Indians (not the people with the extreme positions) would neither prefer to covet the land of pakistan nor its people and would see any reunification as an event that could only worsen religious riots and overwhelm India in other ways. So, the first thing they are likely to desire (rightly or wrongly) is the breakdown of Pak because they might feel that to be a practical solution to Kashmir and other problems and to keep China at bay. But once Pak disintegrates, it is possible, that Indians would over time get more accustomed to the idea of reunification. But these are all only possibilities.