Before you go, ask for the basics in writing: ownership documents, approved plans, the age of the building, the maintenance arrangements and exactly what is included in the quoted price.
Ask about water and power: the source of water, the storage capacity, the generator or backup arrangement and the typical monthly cost. In many Indian cities these matter more than the fittings.
If there is an association or community, ask for its rules and its most recent accounts. Pet policies, rental restrictions and renovation approvals are easier to discover now than after you move in.
On the day, take notes and photographs where permitted, and revisit at a different time of day if light, traffic or noise could influence your decision.
Always verify legal and financial details with qualified professionals before committing. A good advisor will encourage this rather than discourage it.