Vedic civilization started in modern Pakistan and then moved east word into modern Pakistan. Hinduism itself only became called that by the British before that there was no name for the religion people followed because British wanted to make sense of all the different beliefs in the subcontinent. So yes Pakistani ancestors converted from their old religion but they also were the ones who gave said religion to your ancestors.
In essence they converted your ancestors.
Indus Writing Conclusion
The Indus script represents logo-syllabic writing. This means that it does not constitute such a closed system of single-valued graphemes as the syllabic and alphabetic scripts, which could be cracked as wholes. Rather, individual signs may be interpreted one by one, and many of the graphemes are likely to
remain eternal mysteries.
Taken from this dude- Asko Parpola
Asko Parpola - Wikipedia, the free encyclopedia considered one of the top academics but even his theory is questioned by others who have their own theories, the only thing everyone has in common is that no one knows whose right. Hence they have never been deciphered.
Funny because Darius is the original source, the Greek term was a translation of his accounts which dropped the H hence ind portion of india. Darius was describing his conquest of what he considered India.