Can I add credit card to wallet in India

No process.

Apple Pay is not supported in India, and as such no cards can be added to the Wallet App.

click here ➜ Places that support Apple Pay - Apple Support

Apple Wallet and Apple ID (payment methods) are 2 unrelated and separate things.

This may help:

Add a payment method to your Apple ID - Apple Support

Copied from the link above:

• If you can't add a payment method, make sure that the payment method is accepted in your country or region.