All Boeing 737 Max 8 aircraft being operated by Indian airlines have been grounded, Civil Aviation Secretary P S Kharola said here on Wednesday.
Thursday will be a "challenging" day, he told reporters.
Lifting the ban on the aircraft will be based on inputs from various agencies and it will not happen soon, Directorate General of Civil Aviation (DGCA) chief B S Bhullar said.
The DGCA announced its decision to ground the aircraft on Tuesday night.
SpiceJet has 12 such aircraft in its fleet and Jet Airways has five, which have already been grounded.
Kharola said SpiceJet will adjust most passengers in its own flights. If the need arises, other operators will pitch in.
Operators have also agreed not to indulge in "predatory pricing", he said.
The decision to ground the aircraft came days after a 737 MAX 8 aircraft operated by Ethiopian Airlines crashed near Addis Ababa, killing 157 people, including four Indians.