Yes, you can file RTI appliation to The Railway Protection Force (RPF). It is a security force, established by an act of Railway Protection Force Act, 1957. It is governed by the Ministry of Railways (India). Hence, it is a Public Authority Under section 2 (h) of the RTI Act, 2005.
You can file the RTI application to designated PIO under section 2 (f), 2 (j) and 6 (1) after paying the requisite fees, seeking the attendance register/record of the said examination. In the application you must mention your roll number, name of examination and the date of examination.
To further know the procedure for filing RTI's to central website please visit https://onlinerti.com/how-to-file-rti-online-for-center or https://onlinerti.com/