Offices and shopping malls are upper-middle class things in India. They would not come close to holding the entire population. There would be millions of people dying if temperatures got that high.
The point is emergency management here. And I'd bet anything that somewhere there's a workable plan drawn up for exactly this kind of occurrence.
[1] https://en.wikipedia.org/wiki/Retailing_in_India#The_Indian_...
Aside from ACs having a limit on cooling far below “everyone packed in a building”, if you’ve ever done business in India, I don’t see how one could assume there would be a plan drawn up for this grand of a scenario, much less many smaller scale scenarios.
There's vastly more to India than a few metro cities. A quick google search reveals that around 65+ % of Indian population lives in rural areas.
India is in for some very dark times if the climate situation gets worse. The positive lining in the cloud is that we have some measure of political stability for the next 5 years.