 Opened in 2010 , Green Line ( Line 4 ) is the fifth line of the Delhi Metro network and the first line on standard gauge , as opposed to previous broad gauge lines . It runs between Inderlok ( station on the Red Line ) and Mundka with a branch line connecting the line 's Ashok Park Main station with Kirti Nagar station on the Blue Line . The completely elevated line , built as part of the Phase @-@ II of Delhi Metro runs mostly along the busy NH 10 route in West Delhi . The line consists of 17 stations including an interchange station covering a total length of 18 @.@ 46 <unk> line also has the country 's first standard @-@ gauge maintenance depot at Mundka . The line was opened in two stages , with the 15 @.@ 1 km Inderlok – Mundka section opening on 3 April 2010 [ 1 ] and the 3 @.@ 5 km Kirti Nagar – Ashok Park Main branch line on 27 August 2011 . On 6 August 2012 , in a step that will improve commuting in National Capital Region , the Union government has approved extension of Delhi Metro from Mundka to Bahadurgarh in Haryana . The 11 @.@ 18 km metro stretch will have seven stations at Mundka Industrial Area , <unk> , Tikri Kalan , Tikri Border , Modern Industrial Estate , Bahadurgarh Bus Stand and City Park between Mundka and Bahadurgarh . 
