Hello there. Hope you are doing good. I would like to tell you that roll number is the unique identification of a student which helps the university to maintain the database distinctly from other students. That is the reason why roll number is required to know the result as all the details are linked to your roll number only. You can check for your mail id for the roll number. You must have received it at the time of admission. If you are unable to find it, you can contact student affairs department of your college.

I hope you found this answer helpful. Good luck for your future.