The categories of Website and Mobikul can be merged with the help of an add-on Mobikul Merge Categories
In the admin panel, under Mobikul the admin needs to go to Configuration>Merge Categories.
The above pop up appears, in the above screenshot-
1- Create all remaining Website categories on Mobikul- This creates the category on Mobikul as in Website.
2- Link all Products with corresponding Mobikul Category- This will link the products with the respective Mobikul categories.