A form which has two field Role and a Tree View Menu with checkboxes. I want to assign menus to role so that if a user with that role login the user would be able to see only those menus that have been assigned. The menu would be shown as dropdown to the user
I think this module will do what you want: Menu Per Role
Assuming Drupal 7, create different menus, one for each role. Then configure the menu blocks: place them in the same region and restrict each one to the respective roles through the
As Joe suggested Menu Per Role module is best for you, it will give you "Restrict item visibility" option through which you can set the visibility for different roles, i have used this module for the same purpose and it works fine for me.