Hey there! Nice to meet you!
Unfortunately, the Roblox gift card may have been temporarily out of stock in India. You will need to wait for the Rewards team to replenish the codes.
In the meantime, I would recommend saving your rewards points and checking the Rewards Store from time to time.
If you feel the need to contact Microsoft Rewards Support, you may submit your ticket through the link below:
https://rewards.bing.com/support
You can also provide feedback on your suggestion about the rewards points on https://rewards.bing.com/
Click "Provide Feedback" at the bottom left corner of the page > then submit your feedback.
Thank you for your understanding! Please let me know if you need anything else.
Best regards,
Darhyl