The analogy of Palestine completely ignores history. Part of Palestine under Israeli control was occupied by Israel in 1967 war. Legality of accession of J& K to India was never in doubt and has been accepted even by the Security Council. Article 370 is a provision of the Indian Constitution, and hence part of our domestic jurisdiction. Its future has to be decided in accordance with our democratic processes, in which different parties may have different views.
The fate of Catalan movement in Spain and Kurdish movement in Iraq shows there is no international support for secessionist movements in independent States.