if you look at https://www.apple.com/watch/cellular you will see the same model number is correct for India and for Europe, so the watch will be compatible. However, there are a few potential problems for the cellular function.
The Apple Watch eSIM does not support roaming, so if you are away from your home network (roaming service with iPhone) the watch will only connect through the iPhone and will behave like the Apple Watch GPS model.
If you are planning to buy in India and connect the watch (and iPhone) to an Italian (Venice) cellular account you should check with the Italian network that they will accept and activate a watch purchased from India. The watch is exactly the same model, but some networks have been found to refuse devices purchased in other countries.