Adding additional provider is quite easy with a few steps. All you have to do is :
1. Download additional providers packages from http://hybridauth.sourceforge.net/download.html#index
2. you will get a zip file, unzip it and look for hybridauth-vkontakte folder in it.
3. Once you find that folder, you will see another directory named 'Providers' and a file file in it named 'Vkontakte.php'.
4. Copy this .php file to our plugin in socialAuth-wp->hybridauth->Hybrid->Providers.
5. Next, go to socialAuth-wp->hybridauth->config.php and at the end of providers array add followings lines:
"Vkontakte" => array (
"enabled" => true,
"keys" => array ( "id" => "", "secret" => "" )
6. Login to your WordPress installation by Admin user and in the SocialAuth-Worpdress settings, Vkontakte started appearing. It will be disabled initially, enable it by providing "Id", "secret" values.
7. This is it. You are done.