When VNC Server is installed on RHEL6 or CentOS 6, in some instances required fonts are unavailable.
During the installation process, the vncinitconfig utility is run to set up the default font path, amongst other things.
This utility has two ways of setting the default font path: from xset, or from xorg.conf. If VNC Server is installed on a headless machine, or using Anaconda, it doesn't have access to a running X server so xset won't work during installation.
The X that ships with RHEL6 includes various font paths that are built in to the binary, including "catalogue:/etc/X11/fontpath.d", which needs to be added into Xvnc's font path. If that entry is added, VNC Server will start correctly.
The problem is that vncinitconfig can't read that entry out of the config file because it's hardcoded into the X binary instead.
After the installer completes, log in to the console (for example, via VNC Server in Service Mode) and re-run "vncinitconfig -config" (it needs to be run as root or using sudo). Running that command from SSH or an Xvnc session won't work, it just repeats the problem. If VNC Server can talk to a real X server, it is fine.
If there is no X server on the console, then the font path will need to be configured manually. In /etc/vnc/config.custom, set "-fp catalogue:/etc/X11/fontpath.d,built-ins" or add "catalogue:/etc/X11/fontpath.d" to an existing font list.