Make sure
-it doesn't have any room rent capping
- Zero Co pay clause
-Waiting period Pre-existing diseases (2yr or less)
And should offer Super top up (if you are planning now or latter, ideal to go for same company).
Before taking any Health insurance please declare all health related issues (Sugar/ BP/ Cholesterol/ even Thyroid etc)
My recommendation- ICICI Health Shield/ HDFC Health optima