Multi user registration As per the requirement, we need to have two separate registration forms student and companies with different kind of fields.

We planned to use current drupal registration as student registration form with multiple custom fields. (And the values will store in the users table of DB)

Now please provide us a kick-off for creating custom company reg. form which have different fields compare with the student reg. form and store the values in separate table in the DB.

Kindly suggest us.
I'll use default registration for students. Submit of second form will add different role (and register too).

Check this module too: http://drupal.org/project/user_role_field/