manish1380 wrote:
As I mentioned in my question, the band supported by Indian telecom provider Jio matches with the band supported by US version of the Apple Watch series 7, in such case what would stop it from functioning in India, are there any additional checks built-in like source IP address etc. ?
The Indian carrier would stop it from working. It is known many carriers will not activate a watch that was not sold in the country.
The Link I posted above even states it will not work (Apple Watch - Carriers - Apple):
To cover the LTE and UMTS bands used around the world, there are two separate cellular models for Apple Watch Series 7 and Apple Watch SE. They have been optimized for use in the country of purchase, and not all models work in all countries or regions. There is no single model that supports cellular service worldwide.
But you are welcome to try.