Chennai Metro Rail (CMRL) has invited tenders for two detailed project reports that would extend its rail network to Chengalpattu in the south and extend Corridor-5 to Wimco Nagar in the north as part of a second wave of expansion beyond the operator's corridors under construction. The move signals an acceleration of planning for suburban links and interchange nodes. The larger of the two studies covers a roughly 27km extension from the planned Kilambakkam metro station to Chengalpattu under Corridor-1, Phase I. CMRL floated the tender at an estimated cost of Rs 21.6 mn. The proposed line would extend the Chennai Airport–Kilambakkam metro project for which CMRL submitted a DPR to the state government in February 2025. That project envisages a 15.46km elevated corridor costing Rs 93.35 bn and including an elevated road to link Chennai Airport with the Kilambakkam bus terminus via 13 stations; an official said the authority was awaiting clearance from the centre. The second tender, at a cost of Rs 8.8 mn, covers an 11km extension of Corridor-5, Phase II, running from Assisi Nagar to Wimco Nagar in North Chennai to strengthen connectivity in the northern belt by linking into the existing Wimco Nagar metro station. Wimco Nagar is being recast as a transport interchange with Indian Railways, Chennai Metro and the Chennai Unified Metropolitan Transport Authority (Cumta) aligning plans to integrate suburban, regional and urban mobility at a single node. Officials indicated both detailed project reports were expected to be completed within four months, allowing CMRL to finalise alignments and funding proposals. The tenders underscore an emphasis on network expansion and multimodal integration as the agency prepares subsequent construction phases.