It is not a good idea to underestimate India even if their armed forces are weaker than China in all aspects.
They do have an ace up their sleeve which is their control of the Andamans.
The amount of economic damage to China if a blockade is launched is not worth it even though China will destroy the Indian armed forces and its economy.
Destroying the armed forces would automatically place the idea of India controlling the Andamans completely out of reality.
India has no right and no ability to control international trade routes. China itself does not and never even suggested such a ridiculous thing even in waters it has extremely tight control over. It would be illegal and not only be damaging to China's economy. Has China ever considered blocking everyone else's trade apart from its own in SCS? No. Even if it were to administer the entire field of islands there and control everything within the 9 dash line, they would not overstep such a stupidly obvious red line.
Although this is a common fantasy of some Indians, India can no more control trade flowing through Andamans than I could control what colour cars pass through the road in front of my workplace. It isn't up to India like it isn't up to me.
India has no military power to block merchant ships. Let's forget for a second that such an action from India would be met with harsh responses not only from China. In reality, no military tools even need to be used. The threat of engagement would be enough alone if Indian leaders were somehow more stupid than most attribute to even consider carrying out such a thing. If China were to cut off US trade ships from accessing their destinations and the US, it would be justifiable war and such a thing would be unthinkable for China to even consider.
Basically if India ever tried to cut off the Malacca strait, China would sink two out of two of their carriers from the comfort of a few AshBM launches from southern central China. Within hours, the Indians would understand the foolishness of such an idea. It is unthinkable. Of course it remains in the imagination of Jai Hinds as a viable option they have. Something they keep telling themselves but know they cannot carry it out and as long as it's only talked about as something they can do, they will never need to try it and find out as long as it remains an Indian wetdream.