Please some one tell me how can I position modules like slider or banner in header or how can we define additional regions for the modules.
This guide helped me:
http://www.mywork.com.au/blog/create-new-module-layout-position-opencart-1-5/
I was using 1.5.6.1 Opencart version.
You can learn from controller/common/column_right.php
Check module position (line 50), you can adapt it to "header":
$module['position'] == 'column_right'
Set the output (line 69), you can adapt it to something like "header_mod" :
$this->data['modules']
You need to modificate module at admin to show additional module position.
There is no "header" module position options at admin page.