The airport regulator shall in another week decide when the airlines have to shift their operations.
The Bench also said that if the airlines failed to approach DIAL, the airport regulator was free to send them a communication about shifting of their services.
The high court's decision came on Indigo and Spicejet's plea challenging its single-judge order of December 20 last year, upholding DIAL's decision to partially shift the operations of private carriers Indigo, GoAir and Spicejet from Terminal-1 (T-1) to Terminal-2 (T-2) at the IGI Airport.
On October 21 last year, DIAL had asked the three airlines to shift their flights to and from Delhi to Mumbai, Kolkata and Bengaluru to T-2 from January 4. All other flights of the airlines would continue to operate from T-1, the airport operator had said.
While upholding DIAL's decision, the single judge had given the airlines time till February 15 to partially shift their operations.
GoAir shifted all its operations to T-2, saying partial shifting of its operations would "kill" it as it was a smaller airline.