create block region in drupal 6

Open theme_name.info and add regions like

regions[left] = Left sidebar
regions[right] = Right sidebar
region[header] = Header
regions[content] = content
regions[footer] = Footer

regions[top] = Center

regions[center] = Center
regions[custom_regions] = Custom Regions

regions[custom_regions1] = Custom regions1

 add in page.tpl.php file

1. <div>
2. Custom region blocks will go here...
3. <?php print $custom_regions?>
4. </div>