Then Hyderabad and Junagarh are legally not a part of India.Knowledge of Law is important. Its Apple and Orange Comparison. Instruments of Accession is just not mere document. It is the only document that legally recognise. In the same vein Gilgit Baltistan cannot get legally merged with Pakistan.
Don't you understand?
These states acceded to Pakistan legally!
But they were militarily occupied by India on the justification that their population is majority Hindu who want to align with India, and it geographically suits. So, therefore in similar spirit, we have the full claim and right to Kashmir.