@alpha202bd it makes no difference where the phone is located as long as the following are satisfied:
enable provisioning on your PBX with your desired protocol, configure System Admin (ports and provisioning protocols) and Firewall as necessary
Configure the zero touch redirect server with the provisioning details for your PBX for your phone(s), ensuring to include the necessary provisioning authentication (if configured) and port.
When the phone is first powered up it will contact the zero touch server for its provisioning details. As long as the phone is able to reach the zero touch server, and your PBX provisioning server, it will provision and register.
If you need to reset anything, setting the phone to factory default will force it to resync with the zero touch server again.