Hey there Teenderu Vaishnavi
thats a good question and welcome to the Microsoft Q&A platform.
As Quotas are applied per resource group, subscriptions, accounts, and other scopes. For example, your subscription may be configured to limit the number of cores for a region. If you attempt to deploy a virtual machine with more cores than the permitted amount, you receive an error stating the quota has been exceeded.
I guess you need to request a quota increase, go to the portal and file a support issue. In the support issue, request an increase in your quota for the region into which you want to create the VMs.
Toi check the usaage.
Select your subscription => Under Settings => Usage + quotas => Use filter to select tier and region => Check usage of Total Regional vCPUs => If the usage is full, you need to click on Request Increase to increase the limit of cores in the region.
Let me provide you the link below to raise the req
If this helps kindly accept the answer thanks much.