Q. Can I manage Windows Server 2012 and 2012 R2 using Server Management Tools?
A. Server Management Tools (SMT) are the Azure-based management toolset for Windows Server that enables many aspects of management including device management, disk management, event logs, update installation, role and feature configuration and even a PowerShell window. The tools require WMF 5.x (https://www.microsoft.com/en-us/download/details.aspx?id=50395) to be installed on the machine being managed which is native to Windows Server 2016 (even Nano Server). To manage Windows Server 2012 and 2012 R2 WMF 5 must be installed along with the SMT provider. You can manually install these components or if you attempt to manage a 2012/2012 R2 instance from SMT you will be prompted if the requirements should be installed automatically (via the SMT gateway that runs on-premises) as shown.
Once deployed the 2012 and 2012 R2 instances can be managed with SMT.