A postmortem report said he died from excessive oxygen entering his lungs, according to the Indian Express. Authorities are investigating the incident.
Three people — a doctor, and two hospital assistants — have been arrested on suspicion of negligence.
"It is a tragic incident, and we will cooperate with police officials," Ramesh Bharmal, the dean of Bai Yamunabai Laxman Nair Charitable Hospital, told NDTV news channel.
MRI machines work through extremely powerful magnets and radio waves that scan the body and give an image of internal tissue. When a machine is on, all metal objects must be kept away from it.
Government hospitals in India are often short-staffed, overcrowded and ill-equipped to deal with the huge flow of patients. Patients' relatives are often asked to help hospital staff by carrying stretchers and equipment.
The hospital's staff said it was unclear why Maru went so close to the machine holding the canister, and why the machine was switched on while he was there, according to reports.
Family members said the hospital tried to shift the blame. "The ward boy asked him to help. They said it was okay. ... Instead of taking responsibility, the hospital workers scolded us for Rajesh having gone too close to the MRI machine with the cylinder in his hand," Priyanka Solanki, Maru's sister, told the Indian Express.
The chief minister of the state of Maharashtra has announced that 500,000 rupees ($10,700) in compensation will be paid to Maru's family.
Accidents involving MRI machines are rare.
In 2014, two hospital workers were stuck in an MRI machine for four hours in New Delhi, also because of an oxygen cylinder. In 2001, a 6-year-old boy in the United States died after an oxygen cylinder flew across an MRI room and damaged his skull.
