If you use standard Laravel table and field names you’ll have a much easier time getting this to work.
Firstly, your tables don’t need the _tbl suffix - they are already tables in a db.
Your tables can just be ‘countries’ and ‘ universities’
Secondly, your ref_country_id should be just country_id. This way you don’t need to define the $fk. Also given you’ve already got region_id in that table, the region_id is also a foreign key so a variable named $fk isn’t the only one.
In your view, if you’ve got a single university you should be able to display the country as such
$country = $university->country->name;
Also, to follow convention, you don’t need to suffix Model onto the end of your model names. Follow conventions, and it’ll make all your dev easier (and much easier for others to debug).