Hello khemmala,
Thank you for reaching out to the Microsoft Community and I'll be glad to assist you today.
It seems you're having trouble purchasing a product or service from the Microsoft Store. If you’ve recently moved to a new location, you’ll need to change your region. Make this change if you’re planning to stay in the new country for a long time.
1. To change your Country/Region in Windows 11 -
• Go to Settings > Time & language > Language and Region.
• Under Country or Region, select your New region.
• Restart your computer.
To change your Country/Region in Microsoft Store Online-
https://www.microsoft.com/store
• At the very bottom of any page, select the World icon 🌏︎ to choose your language and region.
2. To Add a New Payment method -
• Sign in with your Microsoft account on the Link below.
https://account.microsoft.com/billing/payments?...
• Select + Add a new payment method and follow the instructions.
• The payment method will appear as an option during the checkout process for your next online purchase.
For reference, please go through the Microsoft Self-help articles below.
➛ Add a new bank or credit card to your Microsoft account -
https://support.microsoft.com/help/c39dbc30-bc8...
➛ Change your country or region in the Microsoft Store-
https://support.microsoft.com/help/5895e006-34f...
If you are still having issues with the Purchase, you will need to contact Microsoft Accounts & Billing support from the link below.
https://support.microsoft.com/en-us/contactus/
I hope this information helps. If you have any questions, please let me know and I will be happy to help you further.
Best regards,
Gunasekar N