Doctors at Bangalore's Narayana Health City described the complexities of the case to local reporters at a news conference Thursday.
The boy, who has not yet been named, was born with polymelia -- a rare congenital birth defect that results in extra limbs or organs, which are usually deformed.
"These are problems that happen from time to time and (are) irrespective of socio-economic status," said Dr. Sanjay Rao, a senior consultant pediatric surgeon at Narayana Health City who performed the procedure.
Rao told CNN the boy's parents gave him permission to discuss the case publicly.
Polymelia is a genetic disorder, which can be caused by chromosomal abnormalities or environmental agents, according to a paper in the Journal of Clinical Imaging Science.
The condition can occur when an embryo develops into conjoined twins, but then one twin stops growing but continues to develop extra limbs or organs, which remain attached to the other twin. This was the case for the boy in Bangalore, according to Rao, and it's referred to as "parasitic twins," according to a press release from the hospital.
The presence of an extra twin made the surgery, which took place last week, all the more complex, Rao told CNN.
The procedure required a team of 20 doctors, nurses and technicians.
"Because the anatomy is not typical, a lot of work had to be done before the operation to clearly define the anatomy, what structures are shared between the parasitic twin and the main baby, the blood vessels need to be identified to control blood loss so there was a lot of pre-operative work to build a road map that would help us during the operation," he said.