What's the best place to buy health insurance directly instead of via an agent in India?

First you need to decided which policy.

For this you have to call agents and meet them.

Or you can Google as well.

You can also try online policy comparison sites like

policy bazaar, coverfox or bankbazaar.

Also check Edelweiss tokio insurance. Their products also seem to be good.

Alternatively you can also directly buy from the insurance company websites.