To install language support in CentOS 5 or Red Hat Enterprise Linux (RHEL), follow these steps:
sudo yum install glibc-common glibc-langpack-fr
Replace "fr" with the code for the language that you want to install.
LANG="fr_FR.UTF-8"
Note: The above steps assume that you have already configured the yum repository and have access to the internet. If you don't have access to the internet or if you want to install language support from a local repository, you can use the "yum localinstall" command to install the required packages.