Looks like part of this powerline is actually gone. Seem to have been mapped 16 years ago via https://www.openstreetmap.org/way/30431583/history/1 . Rapid Metro came online ~12 years ago which may have lead to removal of part of the section (or moving) some of it. 

Atleast, I can say some towers exists after Sector 55-56 metro station on ground. I'll try if I can find others and truncate the powerline accordingly via local survey.