15K Brahmos? Do you have any idea what that number means?
That number is much bigger than Soviet or USA total missiles which they prepared to fight WW3!
Firstly, in 2021, India is building a new manufacturing center which can produce 80-100 brahmos ANNUALLY!
New Brahmos Manufacturing Center in India to produce up to 100 cruise missiles per year - Naval News
Secondly, that is maximum possible output of a production, but in reality, there is no country produce at such a speed because those suppliers can't sustain such a level. And it is quite expensive to maintain such a force.