In order to finish the setup of rt, you need to :
 - complete the configuration file ( /etc/rt/RT_Config.pm )
 - run as root :  rt-setup-database  --action init --dba root --prompt-for-dba-password
 - rt is now accessible from http://localhost/rt3/. You can change this in
   /etc/httpd/conf/webapps.d/rt.conf

You can use /var/lib/rt/custom/ to customise it.