The flight was to fly to Sharjah in the United Arab Emirates from the southern city of Hyderabad.
"After the pilot of the Sharjah-Hyderabad flight observed a technical defect in the aircraft, as a precaution the aircraft was diverted to Karachi, Pakistan," Reuters local TV partner ANI said in a tweet, quoting the airline.
IndiGo was dispatching an additional flight to Karachi to bring passengers back to Hyderabad, ANI said.
InterGlobe Aviation Ltd, which operates IndiGo, did not immediately respond to a request for comment.
SpiceJet said on July 5 a Boeing 737 aircraft from New Delhi to Dubai made an emergency landing in Karachi due to a fuel indicator light malfunctioning, prompting the airlines watchdog to issue a warning notice.
India has seen a strong revival in domestic and international air travel in the months following lifting of COVID restrictions.
(Writing by Neha Arora in New Delhi; Editing by Rupam Jain and William Mallard)