The Inner Ring Line is a proposed metro rail line for the Namma Metro's network in the city of Bengaluru, Karnataka, India by Indian Institute of Science (IISc), featuring 24 stations and Six to Eight interchanges with other lines. A study by the institute has projected that the loop line would increase the overall ridership of Namma Metro by 77 percent. The report also concluded that the emissions of carbon dioxide and particulate matter would reduce by 14.8 percent and 18.6 percent respectively, by 2031.
IISc has recommended the loop line as a better alternative for Government of Karnataka's proposal of city wide tunnel roads. The institute stated that the tunnel roads would lead to an increase in the number of vehicles on the road, as opposed to the line, which would lead to a decrease almost twice the calculated increase with the tunnel roads.
As of February 2026, further deliberation on the proposal has been put on hold, as the state government has instead prioritised feasibility studies for Metro extensions to Bengaluru's satellite towns such as Tumakuru, Devanahalli, Attibele, Hoskote, and Jigani.
The proposal to build Metro along the city's Inner Ring Road was mentioned in the government's Comprehensive Mobility Plan (CMP) 2031. It is unclear if the 34-km underground line, which is expected to cost about â¹ 10,000 crore, will be a part of Namma MetroâÂÂs upcoming Phase III or phase VI expansions. The Bangalore Metro Rail Corporation Ltd (BMRCL) is yet to finalise the new lines including the Inner Ring Line.