Hi Manish,
This is currently a known issue with Microsoft (and they are working on fixing it). They have mentioned to deploy the B1s for the time being.
If you would like to find out more information, I recommend checking out the following links:
- https://learn.microsoft.com/en-us/answers/questions/1440468/no-b2ats-v2-and-b2pts-v2-quota-for-azure-student
- https://learn.microsoft.com/en-us/answers/questions/1488476/issue-with-unable-to-create-b2ats-v2-virtual-machi
If this is helpful please accept answer.