Hello Manju,
Instead of creating required fields, it is often a much better practice to use conditional formatting so that as a user visits a view of a form, it is apparent that there are required fields. Then by disabling the ribbon, and using a submit data connection on a button you can control how the user submits. Disable the button until the required fields in the view are filled out, and then enable the submit button.
Let me know if you need more help!
Bre