Hi Shiv Shankar,
A_v2-Series is available in most regions and will shortly be available in all regions and those Vm's are not supported in East-us location.
Standard_D1_v2 Virtual machines in east-us location because size is not Available for capacity reservation.
Goto -----Azure Portal ----->search for capacity reservation group from there you can check the reserved VM's as per your requirement.
https://azure.microsoft.com/en-us/pricing/calculator/
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