Isn’t providing free drinking water mandatory in restaurants?

I’ve been under the impression that providing free drinking water in restaurants is mandatory, not just in Hyderabad but across India. I recall reading news about restaurants being fined for failing to do so. Recently, I had an unpleasant experience at a [Subway Outlet, Jubilee Hills](https://g.co/kgs/eea5KAg). When I asked for drinking water, the guy at the counter flatly refused and insisted that I buy a water bottle instead. This didn’t happen just once but twice. To top it off, he claimed that no Subway outlet provides free drinking water and mentioned that even he brings water from home. I tried reaching out to government officials about this issue—mailing the Food Safety Commissioner and other officials listed on the Telangana government website—but I’ve received no response so far. Can anyone shed some light on this? Is it really mandatory for restaurants to provide free drinking water, or is it not enforced in practice? Also, what steps can be taken to address this issue? Any help or guidance would be much appreciated!