Mentoris is the only theme that supports dropdown menus and it needs to be on version 1.0.6 to support it.
To create a submenu, from your Wordpress dashboard go to Appearance > Menus.
- Select the Menu you want to edit. (If you only have one menu, it should already be selected by default)
- If not already added, add the menu item you want to add to your drop down menu.
- Once added, place it under the menu item you want to be at the top of the drop-down and indent it.