Garland theme and h2 heading On D6.2 I'm using Garland. But instead of generating h1 tags for the title it is generating h2 tag.
What is the best way to make it generate h1 instead of h2?
Should I subtheme it and modify page.tpl.php?
Isn't there any settings or module which can do it?
Subtheme is the answer. The theme is the last line in the rendering of the page which is why you generally can't override it. The H2 tags is most likely hardcoded in the page template which is why you can't alter it.

that being said, you could in a module make garland use a page template that your module has created. This require some complex altering of the Drupal theming system, and is not something you want to do, unless you understand the consequences.