The T-72 Main Battle Tanks and T-90’s built under license in India have formed the back bone of the Army for many years. The Arjun (Mk I) has proved to be a superior a vehicle over the T-72, but has been fighting a battle as it goes up against the numerical superiority of the T-72 & T-90.
The Defence Research and Development Organisation (DRDO) who has developed the Arjun retro-fitted the Mk I turret in to a T-72 hull and fitted the engine etc of the T-90 in to the hull creating a hybrid vehicle – The Indian Tank Ex aka MBT Ex
However the vehicle has not been bought despite successful trials, possibly due to the fact that the true Arjun mobility is better than the T-90 and the hybrid.