I wish to change index.php to index1.php in joomla eg : It is now www.domain.com/index.php?option=com_content..... I would like switch to :

www.domain.com/index1.php?option=com_content......... 

In Joomla, index.php may be the beginning point for every "page" that may be displayed through the Content management systems. Attempting to change that will require extensive changes towards the Joomla core. I'd recommend not doing that, you'll be sorry. You've got a handful of options -

  1. Use index.html or possibly default.php for that other info you would like. You are able to alter the order the web server uses the default file to ensure that among individuals pops up before index.php

  2. Put Joomla inside a subdirectory