Hi Maitri,
Firstly you need to be clear about how much you are planning to invest. Do you want health insurance for family or individual? Health insurance policy should be properly studied and make sure that it fulfills your health needs.
Health Insurance by HDFC Ergo is good option, but I would suggest you to go through more policies.
Personally I would recommend you for Max Bupa which is new company in Indian Healthcare Insurance market. You can avail various flexible health plans for family and individual as well. Opt for one that suits best to your health needs.
I hope it will help you.