Hahaha what a load of sh1t!
Pakistan has always existed, just because we officially became a nation in 1947 doesn't mean we as a people and our nation's land mass popped out of thin air, that's a ridiculous argument. You guys only made up this one because without it you have a pathetic history, almost everything good that ever came out of the sub-continent came from Pakistan, e.g Porus, Kautilya, Panini, Indus Valley Civilisation, Gandhara, Lahore, etc.
We kicked your a55 in 1947, taking 40% of Kashmir from you. In 1965, your invasion was swiftly blunted and reversed and little over 2 weeks. In 1999, we took several key points from you in Kargil such 5353, which even your own army admits gives us complete dominance over the area. At the moment, Pakistan occupies far more Hindustani land than vice versa.
Prior to that, us Muslims made you our b!tch for over a thousand years, constantly waging war and expanding into Hindustan. It gets even more funny when you realise just how much of your culture comes from us too (e.g Hindi is a bastardised version of Urdu, your greatest monument the Taj Mahal was built by a Muslim king from Lahore, you named yourselves after our river, your religion was created in Pakistani Punjab, etc).
Even before Islam, we were still kicking your a55es, e.g Kanishka was a ruler from Peshawar who conquered large portions of Hindustan.
Keep laughing, ignorance is bliss.