Two versions have been developed, one using an imaging infrared seeker and the other with a millimetre-wave active radar seeker. The missile carries a tandem warhead able to defeat composite and reactive armour. The ground version is based on the Sarath vehicle, a version of the Russian BMP-2 infantry combat vehicle built under license in India by Ordnance Factory Medak. The variant used for Nag has a raised rear superstructure, behind which is mounted a rectangular housing which may contain an air-conditioning pack. With the IR version of the missile, targets are acquired using a thermal sight, and are then assigned to the nose-mounted IIR seeker.
Missile guidance is initially by area correlation around the target, then by centroid tracking.
Terminal homing is by area correlation around the centroid. Mission studies carried out in India have indicated the possibility of developing a cost effective hypersonic reusable missile system with a cruising speed of Mach 7 at an altitude of 30,000-40,000m. A missile of this type could be designed for a horizontal as well as vertical launch. It would fly in under ramjet power at speeds of up to Mach 3, then switch to the scramjet to accelerate to Mach 7 for mid-course flight. Once near the target area, the missile would decelerate to deliver its payload or to operate reconnaissance sensors, then return to base.