The incident allegedly took place when the Tata Vistara flight from Lucknow landed in Delhi and passengers were about to exit the plane. The air hostess told the police that she was touched by the man inappropriately when he was getting down.
The airline said in a statement that it would not tolerate abusive behaviour by passengers.
"A cabin crew member on Lucknow-Delhi flight on 24th March reported sexual harassment by a passenger. Vistara does not tolerate abusive or unruly behaviour by passengers that puts safety of its staff and other customers at risk, or compromises their dignity," said the airline.
In December, a young film actress had complained that she was molested by a co-passenger on a Delhi-Mumbai flight of Air Vistara. The airline apologised for the incident and said it has "zero tolerance" for such behaviour. The passenger, a Mumbai businessman, was charged.