Yes, You can file RTI to Annamalai University for marksheet Verification. Annamalai University, established by Annamalai University Act 1929 which is repealed by Annamalai University Act 2013 by the Government of Tamil Nadu derives the status of a Public Authority, falls under the ambit of the RTI Act'2005. Since, It comes under the ambit of section 2(h) of the RTI Act'2005. Therefore, You can file RTI to Annamalai University.
Please click "Annamalai University Act 2013" in the home page of the website www.annamalaiuniversity.ac.in to know about the powers and duties and functions of the officers of the Annamalai University and other information needed by anyone to exercise the Right to Information.
To know further the procedure to file RTI for marksheet verification, you may visit the below mentioned link: