India has bought 10,000 9M119M1 (Invar-M) anti-tank missiles for their T-90 tanks. The Invar is fired from the 125mm gun, like a shell, but operates like a guided missile. The 17.2 kg (37.8 pound) missile is 680mm (26.7 inches) long and has pop-out fins (with a 250mm/9 inch span) that aid in guidance (laser beam riding, controlled by the tank gunner). The missile has a max range of 5,000 meters at a speed of 350 meters a second (14 seconds max flight time). The Invar enables the tank to hit targets at twice the range of the 125mm shells. The tandem warhead can penetrate up to 900mm of armor (35.4 inches). Invar has been around for two decades and India is buying the latest version as well as a license to manufacture another 15,000 of them.
India expects to have about 1,400 T-90s by the end of the decade. The first T-90 entered service in 1993, and India is the largest user. The T-90 is basically an upgraded T-72, which India already builds under license. The T-90 weighs about 15 percent more than the 41 ton T-72. The T-90 has a better fire control system, night vision that is good out to about 1,500 meters, and electronic countermeasures against anti-tank missiles. The autoloader, which often failed in the T-72, is more reliable and that makes the three man crew (commander, gunner, driver) more effective. The T-90 has ERA (Explosive Reactive Armor) in addition to its composite armor.
The T-90 is not as lively as the T-72 and is actually slower on the battlefield than the U.S. M-1 (which has a horsepower to weight ratio of 24:1, compared to only 18:1 for the T-90). The 125mm gun of the T-90 is basically the same as the T-72. However, if you use better ammo, you stand a chance against top rated tanks like the M-1. But that is not what India expects to face. The most likely opponent is Pakistan, which is largely equipped with 1950s era T-55s (actually the Chinese T-59 copy). The Pakistanis also have 700 or so older T-72 type tanks (Chinese T-69 and Ukrainian T-80), but these would be outclassed by the T-90. India plans to have 21 tank battalions ("regiments" in the Indian army) of T-90s (with 62 tanks each) by 2020. Actually, each battalion only has 45 tanks going into combat. The other 17 are for training and replacements.