Yes, You can file RTI to Mangalore Refinery and Petrochemicals Limited (MRPL). MRPL, which was a joint sector company, became a PSU subsequent on acquisition of its majority shares by ONGC. As on 1 April 2007, 71.62% shares are held by ONGC, 16.95% shares are held by HPCL, and remaining shares are with public and financial institutions. MRPL has also been declared as Miniratna, a mini jewel, by Government of India in 2007.
Since it is a PSU, therefore, it comes under the ambit of section 2(h) of the RTI Act'2005 which has the definition of Public Authority. Hence, we can file RTI to Mangalore Refinery and Petrochemicals Limited (MRPL).
You may also visit the following link to know the procedure on filing RTI to Mangalore Refinery and Petrochemicals Limited (MRPL)
https://onlinerti.com/how-to-file-rti-online-for-center
