[eluser]amalik[/eluser]
Hey,
If you want to redirect your users directly to catalog class you can change it is your config/routes.php file by editing $route['default_controller'] = "catalog"; and that will load the index function from the catalog class. If you want to actually create a redirect because of any other reason you can use redirect('catalog'); and that will load your index function from your catalog class.
hope it helps.
amalik