Yes, you can file RTI to Rajiv Gandhi University for Mark Sheet Verification.
Rajiv Gandhi University is Central University, earlier known as Arunachal University, established in 1984. It was established by Ministry of Human Resource Development (MHRD), Government of India and has been a Central University since 9 April 2007. Rajiv Gandhi University, was established by the State Government of Arunachal Pradesh, in 1984. In 2005 the same has been renamed as Rajiv Gandhi University. Hence it is a public Authority under section 2 (h) of the RTI Act 2005.
You can file RTI to the University by addressing it to the concerned "Public Information Officer (PIO)" and by paying the prescribed fee.
To know abut the procedure to file RTI Applications for Marksheet Verification, please refer https://forum.onlinerti.com/247/can-apply-rajiv-gandhi-university-mark-sheet-verification