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.
I read all of your answer. Forget all things. It's very easy to call any module into header section.
Open your catalog/controller/common/header.php
file
$this->data['YOUR_MODULE_NAME'] = $this->getChild('module/YOUR_MODULE_NAME');
Now Open .tpl
file of header, which is located at
catalog/view/theme/YOUR_THEME/template/common/header.tpl
and echo your desire module whenever you want, like as:
That's it. you are done.