After payment, you INSTANTLY receive a license code for Xbox Game Pass Core 1 Month in a personal message on the purchase page.

Activation region: INDIA ONLY
To successfully activate the code, there must be no active subscription and you must have an account and IP address in India. Microsoft has changed the code activation policy, the code is activated only on a new account initially with the country and IP address of India without changing them.

Activation:
https://redeem.microsoft.com