Create node and photo gallery during installation of Drupal 6 I want multiples Node installation with Primary and secondary links, and also want to create Photo Gallery While Installing Drupal.

Is it possible to install and create nodes during installation?
The short answer: Yes!

You would need to use an installation profile for this.  With an install profile you can enable and configure modules, create new content types, add content, etc. 

Here's one place to start:  http://drupal.org/node/1089736