1. You don’t have to change your phone number in order to switch to eSIM. Instructions might be different across telecom communication companies but as an Airtel customer, I just had to send an SMS , Receive a QR code via email, scan it and that’s it.
2. There’s no reason NOT to buy a phone from US if the price difference is more than 15-20k. I personally wouldn’t do the hassle if the difference is 10k or less.

1st google search resulted in this

https://www.jio.com/en-in/esim