I would like to install RealVNC on Ubuntu Mate as it would have installed on Raspbian Jessie.
Through RealVNC packages are form the Debian repo, i suggest I'd suggest you install gdebi and then navigate it to the package for installation. Or you can use
Desktop Sharing (which is from the Software Center)
You can get the deb packages from here: https://www.realvnc.com/en/download/vnc/raspberrypi/
Extract the deb files (there's one for the server and viewer) from the downloaded tar.gz and install with:
sudo dpkg --install <deb_filename>
There's not guarantee it'll work though, since RealVNC only officially support Raspbian.