Render a custom form in a custom template
You need to render your form in the template. Simply calling drupal_get_form won't suffice. To render the form use following:

drupal_render(drupal_get_form('form_nam'))

You also need to ensure the following:


In your custom form #theme parameter is set to appropriate theme function.


Further the hook_theme implementation is correct.



Refer this link for a working example