Hi Corticalcolumn,
This feature needs more customization, you should search a menu module on JED
<blockquote>Hi, I would like to make new menu in topmenu-right position (where you have our gallery/our photos/about joomla in demo), however with usinf mega menu</blockquote>
Open file templates/ja_nex/blocks/topmenu.php, you can see code defined module position.
<blockquote>I would like to place there K2 Login and Your Basket from Virtuemart there. Is it possible? I was trying to do it similar to items from main menu but without success. Can you write me how to do it and configure mainmenu_mod for that menu? </blockquote>
Regards