You say that when you try to install Roon Remote (Core maybe?) things are not working. Could you be more specific as to what isn’t working. It is possible to install Roon onto Server 2012 R2 but it’s not as simple as the install onto Windows 10.
Have a look at these links - might give you some more information that will help getting Server 2012 R2 up and running.
I’ve had Roon Core running on Server 2012 R2 so it is possible 
https://community.roonlabs.com/t/install-for-roon-on-intel-nuc-win2012r2-essentials-using-audiophile-optimzer/1560
https://community.roonlabs.com/t/roonserver-on-windows-2012-r2/3225/6