An official statement said the statue of the "champion of country's independence" would appeal to a large number of visitors.
Over 10,000 people visit Rajghat daily and several foreign dignitaries pay homage to the "Father of the Nation" at the simple black stone platform marking the place where he was cremated.
"The new statue would offer another spot for them to pay their respect to the great soul," the statement said.
Built at a cost of Rs 8.73 lakh, the statue, sculpted by the renowned artist Ram Sutar, is installed in the parking area of the Rajghat Samadhi Complex.
The famous message of Gandhi, "be the change you wish to see", is inscribed on the front side of the pedestal.
"Installation of the statue is a part of a large number of improvement works at Rajghat undertaken during the last three years," the statement said.
Naidu also inaugurated an Interpretation Centre at Rajghat. The Rs 59 lakh facility would enable interactive learning about the life and works of the Mahatma through digital display using LED screens.
"Visitors can watch films, life events, listen to speeches of Gandhiji besides participating in quiz."
The Samadhi Complex also got a new administrative block, built at a cost of about Rs 75 lakh, which is equipped with visitors room, publication unit, staff room and drinking water facility.
A room christened 'Bapuji Kakhya' in the school as a mark of honour to the 'father of the nation' was also found ransacked, with cigarette butts and empty liquor bottles strewn around, a police officer said.
The matter came to light when some locals entered the school premises on Sunday, after noticing that a couple of trees planted inside the compound had been felled, he said.
Upon entering the compound, they found the room open and the head of the statue lying on the ground, the officer said.
The incident is suspected to have taken place on June 14, and could be the handiwork of some anti-social elements as the upper primary school was shut for the summer vacation, Inspector In-Charge of Sahadevkhunta Police Station, Subhransu Sekhar Nayak said.
Nayak, however, ruled out any political angle to the episode.
A case has been registered and investigation is in progress to identify those involved in the incident, he added.