You can of course install whatever remote server you want inside the VM but aside from that you can connect to a VM directly using VRDP.
But you can also manager your entire virtualbox instance using RemoteBox ( http://remotebox.knobgoblin.org.uk/about.cgi ) or from a web GUI using phpVirtualBox ( https://sourceforge.net/p/phpvirtualbox/wiki/Home/ ).
I'm sure there are other options as well.