You are concocting the potential future sequence of events according to your own whims and delusions. Let me place a scenario and tell you something. As soon as, a major civil war erupts between Hindus and Muslims, in India; far before, any mass exodus of Muslims, from India to Pakistan, which you are envisioning, an all out war would certainly, without any iota of doubt, break out between the two countries. Pakistan would never wait for the time, when forced migration of Muslims would potentially take place. Then, whatever may be the result of that war.
Having said, what I have said above, in response to your poisonous posts, what I believe is that, with time, both Hindus and Muslims of subcontinent will inadvertently learn to coexist peacefully; because there is not other way.
Trust me.
By the time the killing starts, the Hindus would have squeezed your apparatus to the point where you will be mining your borders and lining up your forces on land see and air to keep the swarm of humanity out.
And you will fail. Thanks to your geography. Your poverty. And your shared faith.
Cheers, Doc