Your Azure free account includes a limited quantity of free services for 12 months.
As long as you are within the limits, you can create services for free in any region where services are available.
For example, you get 750 hours of a B1S Windows virtual machine free each month with Azure free account. You can create the virtual machine in any region where B-series virtual machines are available. Azure doesn't charge you unless you exceed 750 hours.
For example, a customer in the U.S. can provision a B1S Windows virtual machine in West Europe and use it for 750 hours for free.
For more info refer to https://docs.microsoft.com/en-us/azure/billing/billing-create-free-services-included-free-account