Increasing Manpower is never an issue as during emergency we can enlist as many as we like. Tbh like China we Should focus military modernization. Advanced infantry gear. And focus on our missile capability both in quality & quantity. Subsonic cruise missiles like Nirbhay needs to be improved. Longer range MBRLs, Get more bombers, attack helicopters. We are very light on Submarines as well. Need at least 2 aircraft carriers fully operational.
If we do this we'll be dominating entire South Asia & IOR.
Since India is a populous nation we get a false sense that we are rich in manpower.
Recruiting in wartime is not easy. Our primary recourse are soldiers who are retired but less than 50 years of age. We may draw some from CAPFs. Some recruitment can be from NCC pool. Overall we will struggle to get more than one million men if there is shortage. Not good for a country our size.
If we have intense war at our land borders, my estimate is that we may need 2-3 million men fighting and similar numbers in reserve. Rest we need for internal security.
Vedic yardstick is that one men from 30% families should be available in wartime for State duty.
The MBRL, bombers are good but not replacement for soldiers. You will need numbers to attack behind the lines.