I've read a lot of comments that seem to suggest that the Arjun would survive most hits from an enemy tank... or even from a missile. The sad truth is that --- in the ninety-year-old contest between tank and anti-tank --- armour-piercing technology is currently ahead of armour technology. The only protection that is effective today is active armour.
In fact, this is the staple argument used by all those who argue today for a 40-ton tank. The argument goes... there is no point slapping on all that heavy armour plate. It's going to get defeated anyway.