As far as I remember, India sent tanks that weighed only around 15 tons in 1971. But, even those tanks bogged down in our terrain. I do not remember the name of those tanks. We have only our NW where tanks can be deployed. A war with Burma or India will not be fought with tanks, precisely speaking. Nature will defend a tank assault. This may be one reason why the military does not want to waste money in tanks.
I am no expert. But, I think, a strong navy, and many anti-aircraft missile system are more important than that. A guerrilla warfare can be conducted if an enemy infantry force enters our territory with artillery. Other than military, BGB (BDR) and Police, more than a million people at any time know how to use small fire arms. They are grouped in militias like Ansars and VDP. An army general always heads these militia groups. It means that these two groups are essentially under the military. It is same with BGB.