He breathed his last at around 3.45 pm at the Medanta Hospital in Gurgaon where he was admitted for renal ailments, according to his family friends.
He will be cremated here on Monday.
Hailing from Karnataka's South Canara district, Rao started his career with the Information Service in the 50s.
He rose to become the Principal Information Officer, the top post in the information central information department.
Known for his humility and efficient communication skills, Rao had served as media adviser to four former prime ministers - Rajiv Gandhi, V.P. Singh, Chandrashekhar and P.V. Narasimha Rao.
Information and Broadcasting Minister M.Venkaiah Naidu described his demise as a huge loss to Indian Information Service fraternity.