This milestone is part of the Pink Line (Reach-6) under Phase-2, which spans 13.76 km from Kalena Agrahara in the south to Nagawara in the north.
https://swarajyamag.com/infrastructure/bengaluru-metro-completes-tunneling-for-citys-longest-underground-line
https://swarajyamag.com/infrastructure/bengaluru-metro-completes-tunneling-for-citys-longest-underground-line
Bengaluru Metro Completes Tunneling For City’s Longest Underground Line
swarajyamag.com