People inherit their history irrespective of the religion of their people. Just like present day Iranians are rightful claimants of the the old Persian empire and history despite them being muslims and giving up Zoroastrianism; same for Egyptians who are muslims now, Babylon which is Iraq and Syria now etc., the Indus civilization was centered around the river Indus which is entirely in Pakistan. All those ancient cities and people living from those ancient times makeup present day Pakistan. Most of the remnants and the people are primarily here now; if an archeologist needs to study Indus civilization he/she has to come to Pakistan. Even if Pakistan as a country came into existence in 47, it doesn’t not mean all the people and this land they live on just dropped from space with no lineage and history. Otherwise with your hateful twisted logic Egyptians have no claim to their ancient Egyptian history and Iranians would be deprived of their old Persian history as well (I dare you to try this with some Iranian members here) - as all the old civilizations were following pagan religions, so by that logic only you Indians are the rightful claimants to all the Babylonian and ancient idol worshipping Arab history.Hilarious. So what what was his name Mohammad Abdul porus al pakistani?
Neither you have any heritage nor Identity. You even claim Indus civilization as your own when it has got nothing to do with Islam or muslims. And there's was no pakistan before 47. British made it to act as a buffer against Soviet invasion.
These people and the land they have been living on is primarily the Indus civilization- Present day Indians have their own history as well such as Sikhs and Tamils, but it’s irrelevant to the history and culture of Pakistanis (maybe Sikhs have a connection due to them being Punjabis).