Hi Ömer Koçbil,
Welcome to the Microsoft Q&A Platform! Thank you for asking your question here.
We understand from your query that you are experiencing an issue while trying to create a virtual machine in East US with the size NC4as_T4_v3 but getting as your quota is full. Please try below steps that help resolve your issue.
Please verify for any stale resources associated with the VM series in the East US region. Navigate to the Virtual Machines, Disks, and Public IP Addresses sections to check for any lingering resources. If you identify any, please delete them to free up quota.
Check the current quota usage, go to the Azure Portal and navigate to Subscriptions. Select your subscription, then click on Usage + quotas and filter with region, to review your current quota limits and usage for the NC series.
Please try creating the VM in a different Availability Zone within the East US region to see if the quota differs by zone or try creating in another region as Azure may limit the availability of certain VM series due to capacity constraints. This can occur if many users in the East US region are utilizing NC series VMs, which may prevent new allocations for that family in the region or its zones.
Try Azure CLI to check the available current quota:
az vm list-usage --location eastus --output table
This command will show the current quota usage for each VM size in the specified region. check for your specific size.
If the above steps don't work, try to increase the quota: From the Usage + Quotas page, click on Request Increase for the NCas_T4_v3 quota then follow the steps to request an increase in the quota and submit the request.
If you have any further queries, please do let us know. If the answer is helpful, please click "Accept Answer" and "Upvote it" as it can be helpful to others in the community.