The defeats at the hands of Bahmani Sultan led Deva Raya II (1425-1446) to investigate into their causes. He summoned a council of his nobles and principle Brahmins, observing to them that his country, in population and revenue, far exceeded that of the house of Bahman, and also his army was more numerous. He requested them to point out the cause of the success of the Muslims and of his being reduced to pay them tribute.
He was told by his Councillors that the superiority of Musalman rulers arose out of two circumstances :”First , that their horses were stronger , and able to endure more fatigue than the weak animals of Carnatic ; secondly , that a great body of excellent archers was always maintained in pay by the Kings of the house of Bahman, of whom Raya had but few in his army. ” Accordingly he at once launched a drastic scheme of military reform ; he admitted the Musalmans into his army on a large scale , conferred jagirs upon them , erected a mosque for their use in the city and offered other facilities for the free exercise of their religion ; and at the same time he made all the Hindu soldiers also learn the discipline of bow. By these measures he managed to raise an army of two thousands Musalman , and sixty thousands Hindus , well skilled in archery , beside eighty thousands horse and two hundred thousands foot , armed in usual manner with pikes and lances.
(Reference: Briggs, History of the rise of the Mohammedan power in India, II, 230-232)
In 1524 Portuguese traveler, Fernao Nunes, visited Vijayanagar empire and reported its army to be 0.6 million men and 24 thousands horses.
A History of Modern India, 1480-1950