Studious and civilized silence on all matters and shenanigans of Pakistan might be the best medicine for now. Make them feel they aren't really that important to us.
The OIC is made up of a bunch of limp, impotent, so called worthless states, who don't have the balls to question the butchery going on in their own so called "Ummah" in the dominions of Syria currently and prior to that in Libya, Egypt, and also currently in Tunisia and Bahrain, Yemen, Iran during its so called elections, and blah and blah going back in time to eternity.
The OIC never questioned the state sanctioned pillaging and mass slaughter organized by the Pakistani govt. when they unleashed the primitive tribesmen on the Shia populace of their own so called lands of Gilgit and Baltistan. Or for that matter the current butchery of Hazaras on a daily ritual basis happening in Baluchistan. Mind you, these mass slaughters are orchestrated by the same terrorist groups which the ISI babysits with funds, support and shelter.
What gall this so called OIC has, to question India or about Kashmir, when it doesn't give a $hit to the above crap happening all over its own Muslim world? It is because these countries or their leaders will piss on OIC if it ever tries to check any of the atrocities they are imposing on their own Muslim population.
The OIC better shut up or if it wants to be seen relevant or credible in any way at all, it should investigate and set its own Ummah home right before venturing out any further.
Well done, do not ever fall for, or give into, Islamist propaganda on Kashmir. Stay the ground, which is that India is a multi-lingual, multi-ethnic, multi-religious and multi-non-religious( atheism, agnosticism) country, which will not countenance movements or separation based on religious hatred or religious fanaticism, nor of ethno-chauvinism.