Hi,
In the portal, please go to your subscription -- Usage + quotas blade. In the search box, type the beginning of the family size you are trying to create and select the Region you would like. For example, type Standard NC
In the search results, find the specific VM family/size and check what your current quota limit is. If necessary, click the pencil on the right hand side to request a quota increase.
Please note some sizes in certain regions are in high demand and you may need to create a support request to potentially get access to them. See screenshot below for example:
Please click Accept Answer if the above was useful. If you still need assistance or have questions please add a comment below.
Thanks.
-TP