The new 9.5 km (5.9 mi) section of the Yellow Line from Dahanukarwadi to DN Nagar was inaugurated on January 19, 2023, by Prime Minister Narendra Modi.

[12] MMRDA officials plan to solve the problem by shifting the location of the proposed rake depot to Malwani near Malad.

[14] On 6 September 2012, the MMRDA sent a letter to Reliance Infrastructure asking them to start work on the metro immediately or face legal action.

[17][18][19][20] On 8 February 2013, then RInfra CEO Sumit Banerjee claimed that the project had not advanced because the MMRDA had failed to fulfill its share of the responsibilities.

[21][22] The state government had since been considering alternative sites for the depot, which might have led to complete change in the alignment of the line and could have required re-bidding for the project.

"[24] Chief Minister Prithviraj Chavan told the media on 30 August 2013 that "it is now clear that Mumbai's Metro II project will now not happen.

RInfra stated, "Due to non-fulfilment of various critical obligations by Maharashtra government and Mumbai Metropolitan Region Development Authority (MMRDA), the project could not take off.

[27][28] In September 2013, the MMRDA appointed RITES to study the feasibility of constructing the proposed 32 km (20 mi) metro line underground.

RITES also studied the feasibility of extending the corridor and merging the 7.5 km (4.7 mi) Charkop-Dahisar metro, proposed as a separate line, with this project.

RITES submitted its final report to the MMRDA in the last week of May 2014, concluding that constructing the metro underground and extending it up to Dahisar was feasible.

[36][37] On 1 July 2015, it was announced that the MMRDA was allotted a 22-acre (8.9 ha) plot in Mankhurd adjacent to the Sion Panvel highway for the Metro carshed.

[39] In November 2015, the Department of Economic Affairs (DEA) cleared the MMRDA's request to secure a loan from the Asian Development Bank (ADB).

[43] A study by World Resources Institute (WRI) India, published in May 2021, estimated that Metro 2A and Line 7 had the potential to create 1.1 million jobs in the city.

Residents of SV Road gathered at the Sacred Heart Boys’ School in Khar to protest the Metro 2B project on 12 August 2017.

[46] Petitions against the project were also filed in the Bombay High Court by the Juhu Vile Parle Development Cooperative Housing Association, the Gulmohar area society welfare group, and the Balabhai Nanavati Hospital.

[50] Metro 2B also faced legal issues concerning the section between Indira Nagar and Nanavati Hospital that passes through a funnel area of the Juhu Aerodrome.

The agency also noted that an underground metro would take 2 years to build and would cost over 5.5 times more per kilometer than an elevated line.

The MMRDA stated that the design of the metro was a "highly technical issue" and that the petitioners did not have the required scientific experience to evaluate it.

The Kurla Terminus station was cancelled in September 2020 because it was in the path of the restricted funnel zone for Mumbai Airport.

Another issue was that the Kurla Terminus station would have been located in between the Santa Cruz–Chembur Link Road (SCLR) rail overbridge and another permanent structure.

Both lines were extended on 19 January 2023, providing circular service between Andheri West and Gundavali via Dahisar East.

[68] In July 2018, the state government granted special planning authority status to the MMRDA in a bid to speed up implementation of metro projects.

J Kumar Infra Projects Limited was awarded both packages in June 2016, and carried out civil work, including viaducts and stations.

[77] The corridor was scheduled to be commissioned in October 2019, but delays in procuring rolling stock and issues with civil works pushed the deadline to December 2020.

[85][86] The MMRDA began a dynamic test and trial run on the 20 km stretch between Dhanukarwadi and Aarey (including a portion of Line 7) on 19 June.

[88] The stretch between Dhanukarwadi and Aarey received provisional approval from the Research Designs and Standards Organisation (RDSO) in January 2022.

[107] In March 2019, the MMRDA altered the alignment of the proposed route at BKC Road to avoid it passing in front of Shiv Sena president Uddhav Thackeray's residence.

[108] On 4 February 2020, the MMRDA terminated the contract awarded to Simplex Infrastructure and the RCC-MBZ joint venture over delay in completing the work.

[40] The MMRDA allotted ₹340 crore (US$39 million) to the DMRC to implement and commission rolling stock, signalling and telecommunication work for the Metro 2A and Line 7 corridors on 26 November 2016.

On 2 March 2019, the Union Ministry of Finance stated that it signed a $926 million loan agreement with the ADB to fund construction of Lines 2 and 7.