I think fossunited can host something like https://foss.events, but for all foss events in India. i think that might be a lot more intuitive than a calendar tbh
It’s a good idea but I (personally) would prefer it if the Community creates and maintains this instead of the Foundation doing it. The Foundation can definitely help financially (e.g. one-time domain purchase, ongoing server costs) but the IMO the Community should actually take care of maintaining the page e.g. updating it with events, regular software upkeep, etc.
In my humble opinion, both should exist. I subscribe to the public calendar on my phone and on thunderbird and i have easy access via the applications that i use multiple times a day, every day.