To view the regional quota consumption and limits, you use az vm list-usage. This means if you will create a VM, you need to ensure that your selected VM’S family vCPU requirement fits the remaining vCPUs available for that family in the region.
az vm list-usage \
--location southindia \
--query "[?name.value=='cores' || name.value=='standardDSv5Family' || name.value=='standardDSv4Family'].{Quota:name.localizedValue,Used:currentValue,Limit:limit}" \
--output table
Quota Used Limit
-------------------------- ------ -------
Total Regional vCPUs 0 10
Standard DSv4 Family vCPUs 0 10
Standard DSv5 Family vCPUs 0 0