Months after the Haryana government gave the go-ahead for extending the Metro line to IFFCO Chowk from Dwarka, the Delhi Metro is looking at three options. "The financial feasibility of all three is being looked at. The revised detailed project report will be submitted soon," said a DMRC spokesperson.

The options for the corridor between IFFCO Chowk and Dwarka Sector-21 are extending the existing corridors—the Airport Metro or the Blue line (Dwarka Sector-21 to Noida City Center)—or building a new corridor from Dwarka to IFFCO Chowk.

"The alignment and stations will remain the same for the revised detailed project report. The Haryana government will take a call on which option to go with," added the Delhi Metro Rail Corporation official. Once the corridor is decided, work on the project is expected to take off by next year.

While extending existing lines have been the preferred option for phase-III, extending the Airport line or the Blue line could prove to be a tricky affair, said sources. The Airport Metro has a different ticket structure than the rest of the network and is a high-speed connection. The Blue line, meanwhile, is already one of the most congested and populated corridor and is over 50km long. The daily ridership is around 10 lakh on the Blue line.

"If the state government opts for an independent corridor from Dwarka to IFFCO Chowk, then the Dwarka Sector-21 station would become an interchange station, with connectivity to both the Blue line and the Airport Metro," said a senior official.

The alignment that has been mapped out is the same for all three options, with stations at Dwarka Sector 21, Bijwasan, Gurgaon's Sector-23, Sector-18 and IFFCO Chowk. It's a 12km-long alignment and will connect south Delhi with Gurgaon and bring down travel time drastically. As per initial estimates, the extension will reportedly cost more than Rs 2,000 crore.