Install the rpmforge repo
wget http://pkgs.repoforge.org/rpmforge-release/rpmforge-release-0.5.2-2.el6.rf.x86_64.rpm rpm -i rpmforge-release-0.5.2-2.el6.rf.x86_64.rpm yum install unrar -y
Once you have the package installed, type in the following command to extract the rar
unrar x <filename>.rar
The x tell’s unrar to maintain the original folder structure. Make sure you do this in an empty folder.