In that case how can India claim IVC, as India is also less than 100 years old.
First of all, religion was not the only basis of creation of Pakistan. There were many other factors which were as important and highlighting only religion as the basis of Two Nation Theory is a narrow view which some Pakistanis and majority of Indian Hindus believe:
Religious differences
Governing differences
Civilizational differences
Cultural differences
Societal/Social differences
Economic differences
Political differences
And while you Indians accuse us Pakistanis of using religion as the only basis of Two Nation Theory, you do the same and use your own religious scriptures as authority to prove your identity. The example is very clear from your own statement. You say the while the IVC was discovered only 100 years ago, the Vedas, Ramayana, Mahabharata, Puranas, Vedanta... these are thousands of year old and Indian identity is not based on the IVC exclusively. What are these books that you are talking about – these are your religious scriptures which you base your identity on. You accuse Pakistanis to have used religion to highlight the Two nation Theory – you are also using religion to identify your identity and also geography.
There are many Indian Hindus who state that Rig Veda and other Vedas are words of God and do not represent any history. Yet most of you cite these religious scriptures to highlight India’s history and India’s geography.
When Indians accuse us that Mohammad Bin Qasim is perceived as the first Pakistani, the Indians also use their religious scriptures to outline their history and their civilization and the raison-detre of India’s existence. Get over your own demons before you have the right to accuse others of doing the same.
To prove the fact that IVC is a Pakistani heritage, religion is not used as the reason. It is the history supported by archeology and geography which is used to bring out the facts. Contrarily, Indians use religion and religious scriptures to lay their claim.
There was no Republic of India as well.