You can file RTI Applications to Public Universities only. Private Universities do not fall under the ambit of RTI.
You can file RTI Application to your University to know about the Rules followed for Conversion of CPGA to Percentage marks if your University is a "Public Authority"under Section 2 (h) of the RTI Act 2005. As per Section 2 (h) Public Authority means any authority or body or institution of Self-government established or constituted -
(a) by or under the Constitution,
(b) by any other law made by Parliament,
(c) by any other law made by State Legislature,
(d) by notification issued or order made by the appropriate Government, and includes any-
(i) body owned, controlled or substantially financed;
(ii) non‑Government Organisation substantially financed, directly or indirectly by funds provided by the appropriate Government.
To know more about the procedure to file RTI Applications, please refer https://onlinerti.com/