I am sorry, but that was a silly observation. The Arjuna is closer in weight to European battle tanks, and is very heavy.
@Dustom999 has already identified the key features needed in a tank that fights in this theatre, and it is a useful note to read before posting kindergarten dares.
I have no military experience whatsoever and even i can tell that tanks on mountains are extremely restricted in that theater. General Nathan in the american civil war highlighted the very essence of military warfare by stating "The objective is to get there firstest with the mostest." (the general loved the 'est')
You can deploy tanks on passes and trails but they will be ambushed in a military conflict. If the concept of General Nathan is to be taken then what we need, especially in mountain warfare, as has been shown multiple times is speed. Speed and capturing the heights, the strategic passes and if these get taken, then dislodging the enemy from just a squad that has taken it alone will be a nightmare. I doubt in such an engagement a large target like a tank will make a difference.
Tanks have always been about firepower, protection and mobility. The provide extreme action, protect the infantry supporting them and are fast enough comparatively to take down the enemy. Thus the concept of tank warfare has always been them coming enmase and mowing through the line. Now it is the doctrine of war that war is the only time when a weapons and strategies are fully implemented otherwise its all on paper and all theories. We havent seen armies try to deploy tanks in mountain warfare as a means to rush the enemy and i dont think we will. Mountain warfare is very surgical in nature and with modern warfare, it has become even more surgical. I just cant see how tanks will work, where every step is a danger and not just from the enemy but from the terrain as well.
If we look at what China is planning to deploy then it is thinking about light weight battle tanks and not MBT which are a combination of three types of tanks but light weight. The idea is again mobility however i highly doubt China will be thinking about using tanks as tanks have been used so far. I would the idea of utilizing tanks in mountains is simply to do two things
1. deter the enemy from small surgical tactics where they can come in a small squad and capture a strategic pass.
2. to provide small level firepower where the weapon without the hindrance of the artillery.
In both scenarios i see the weapon as mostly stationary and the thing about a tank is that it fires straight.. If a pass is under the protection of the tank and the enemy takes the higher ground and fires anti-tank ordinance then that tank is doing to damaged with massive dependency on the artillery and infantry.
Have we never wondered why Pakistan and India, very well equipped and very smart armies, never deployed tanks on the LOC and made posts on artillery. I mean they are deployed near the LOC but not on the passes. so why is that? because tanks and mountain warfare is an experiment and a risky one at that which on paper does not look good.
As for Arjun. Arjun is a main battle tank and deploying it in passes and mountain trails and glaciers is extremely moronic. Its not whether the tank is good or not but whether it will be a hindrance or not and bringing an MBT on a mountain where already on paper, it looks sketchy. They are not that foolish. Each ordinance and weaponry is built for a purpose. There are no all-purpose weapons. Each weapon is made specifically for a purpose and, although it may be used for other purposes but its effectiveness will decrease from a 100%. Will you use an ABM system to target opposition posts or tanks? No of course not. It may work but why not use the weapon made for that purpose.