From official website of gaucamole i.e. (http://guacamole.incubator.apache.org)-
Apache Guacamole is a clientless remote desktop gateway. It supports standard protocols like VNC, RDP, and SSH.
We call it clientless because no plugins or client software are required.
Thanks to HTML5, once Guacamole is installed on a server, all you need to access your desktops is a web browser.
Can I setup guacamole on windows server 2012. If yes how ?
It should be possible to run the Guacamole Docker container in the Docker Toolbox under Windows Server 2012. This reduces the overhead compared to a full blown VM like suggested by Bram.