Hindus claim Muslims butchered them by the millions yet there are nearly 1 Billion Hindus in the world, pray tell me with a near non existent conversion rate where did these numbers come from? Do not take it as a slight when I said Indians breed a lot that included all Indians and yes Muslims do the same today.
As for top portion Muslims were already ruling parts south of the plains of North India, most of the areas in the Deccan were being ruled by Muslim sultanates which Aurangzeb defeated and added to the Mughal empire. Bahmani, Deccani, and the Nizam.