Download the .repo file and save it to the correct location:
wget -O /etc/yum.repos.d/x2go.repo \ http://download.opensuse.org/repositories/X11:/RemoteDesktop:/x2go/RHEL_6/X11:RemoteDesktop:x2go.repo
RHEL_6 by the tag for the distribution you are actually using. Available ones are:
RHEL_6. Note that not all of X2Go is provided for RHEL 5/6, as these distributions are very old and therefore more work-intensive to develop for.
Hint: If you are behind a proxy, make sure the proxy is defined in
/etc/yum.conf. Standard yum repos do not use the same connection mechanisms as RHN channels.
Congratulations, you are now able to access the X2Go packages. You may continue by installing
pyhoca-gui or any other of the available packages.