Link to the pic of the prototype
http://www./pictures/arjun-india/p3592-prototype-of-arjun-mk2.html
Some key features of the MK2 include:
-FMBT's engine will be two-thirds the size of Arjun Mark I MBT's engine and will generate 1,500-horsepower. First prototype of the indigenous engine would be ready by 2016. FMBT will weigh 50 tonnes.
-Project to develop the transmission for the tank is being launched. Engine and transmission ( aka "Bharat Power Pack") will meet the FMBT's mobility requirements. So transmission is made locally.
-Volume occupied by the electronics package will be low.
-A total of 93 upgrades, including the advanced air defence gun system for firing at attack helicopters. Missiles firing capability to destroy long-range targets and bring down attack helicopters.
-Panoramic sight with night vision for the tank's commander. An automatic target tracking system to add accuracy when firing on a moving target.
-Explosive reactive armor panel which will comprise explosives in metallic brick form. These bricks will be mounted all round the MBT. When the enemy ammunition hits these bricks, they will explode and retard the energy of the projectile. Tanks armor will not be penetrated.
-Improvements in material, fuel injection and filtration technologies will contribute to the reduction in the engine size without compromising on power.
Source:
DRDO Reveals Specifications of Arjun Mark-II, Future Main Battle Tank (FMBT) | India Defence
The tank will use some foreign components from Israel and France. Mostly electronics.
Weapon and Technology: Israeli laser-based defensive suite on the Arjun Tank
Some dude said that the MK2 might look like this: