All three aircraft were taken out of operation after the collision, said the operator.
The ground equipment belonging to Air India Engineering and IndiGo moved from their position due to the sudden inclement weather, hitting the aircraft parked at Terminal 2, it said.
The private operator also said that the Air Traffic Control had issued no warning (to the airport operator or airlines) about any change in weather.
Air India declined to comment on the incident.
An airline source, however, said that along with three of Air India planes, aircraft of other operators were also impacted due to the hostile weather conditions.
He said that of the three impacted aircraft, two will be back in the operations soon while the third will take a little longer to be fixed.
