Shimla agreement was violated by India unilaterally by bulldozing clause 2,3, 6 in 1984, Shimla agreement didn't explain either a party hold right to invite third party into issue or not thus only approached to both parties for peaceful solution of conflicts or issues hence it has no binding on Pakistan since India violates it.
Since India & Pakistan is strict on CFL in disputed area both countries keep right to get possession literarily but India not on actual grounds as Nahru promised to give Kashmiris right for desired accession.
Even if UNSC resolutions on Kashmir are passed under chapter 6, it was/is the duty of democratic/secular duty of India to respect the mandate of Kashmiri people but not to mass kill to form PDP with frightened, harassed & assaulted innocent people with some purchased leaders thence Pakistan respects UNSC resolutions and will continue to extend its political,moral, strategic support to get free from inhuman, extremist governance.