[7] After clearing the probation as a Lieutenant, Dalvir Singh joined the 10 SF also known as Desert Scorpions, stationed in the arid State of Rajasthan.

[13] As per orders, Dalvir Singh launched his SF team to hit the militants' HQ in the heart of Jaffna town, for searching the defence and for the capture of LTTE senior leadership, and as preliminary to final assault by the infantry troops.

The SF squad of 80, instead of the preplanned 120, was heavily outnumbered yet managed to move out of the open ground and sought refuge in an abandoned house where they holed up while fighting for the next 18 hours, awaiting rescue.

The news of the ambush reached Dalvir Singh and he immediately volunteered to move with the columns of infantry to the area, to establish contact with his SF troop.

With utter disregard to his own safety, Dalvir Singh led his relief team to the objective in the face of heavy militant fire.

[15][16] Dalvir Singh and his relief troops fought for 2 days and extricated the beleaguered SF team of 74 along with its 6 casualties, fighting their way out of the militants' cordon, to the safety of the Palay military headquarters.

He also commanded the elite 52 SAG of National Security Guards, as well as the Counter Insurgency Kilo Force of Rashtriya Rifles which handle Kupwara, Baramulla and Srinagar regions.

[22][23] Dalvir Singh is also credited as one of the core officers who set up and modernized the training strategies for National Security Guards.

[29] He also raised Thar Falcons, an anti-terror police unit,[30] and under his tutelage, they got selected for guarding Cairn India Oil Field in Barmer, Rajasthan.

He launched his team of para commandos to hit the militants' headquarters in the heart of Jaffna town, for searching the defence, preliminary to the final assault.

Lieutenant Colonel Dalvir Singh thus displayed conspicuous courage and valiant leadership in the face of strong militant opposition.