AFAIK Indian states generally had cores of relatively large standing armies, that could be bolstered or maintained with feudal levies. The largest states had armies in numbers of upwards of 100K foot soldiers (depending on the time period), along with several thousands of cavalry and several thousand elephants. I'd imagine minor states would be an order of magnitude less. Specifically in regards to ~1500, Vijayanagar in particular had a rather powerful navy. Since Vijayanagar was basically the most powerful state in this era, and AFAIK was fairly typical, here's a good wiki page. I don't think mercenaries were that widely used.
In GDP, (by modern borders), India in 1500 was basically equivalent to China, (but obviously wasn't united at all.) That's all I really know.
I don't know specifics beyond that, or any numbers.