You can apply RTI Application to know about Marks obtained by you in any Examination held by Any Body terming as "Public Authority" under Section 2 (h) of the RTI Act by addressing the Application to the designated "Public Information Officer (PIO)" and paying the prescribed fee.
To know more about the procedure ton file RTI Applications for Exam related matters, please refer https://onlinerti.com/how-to-file-rti-online-for-exam