The huge number of skulls — about 600 — makes this the largest single human burial in India or elsewhere, said the team, which started excavation works on January 12. Quoting experts’ opinion, sources told Express: “It is the rarest of the burials executed for the victims of a natural calamity. It was a community burial. All other theories, like large-scale massacre of traitors, slaughter of prisoners of war and religious homicide, cannot be validated.”
The experts also dispelled the theory that it was a collection of remains made by occult practitioners of Vamachara (witchcraft). The experts said one ghastly natural calamity that happened in the Deccan in particular, and south India in general — and well-recorded in the history of the region — was the severe famine of 1789-92. This famine is remembered even now in folklore as ‘bones lay unburied, whitening roads and fields. The ground was covered with skulls of the unburied’.
So rather than the skulls being related to some magical purpose, it would appear that the mass burial was a response to the concurrent deaths of many people who needed to be buried quickly. That's a lot less over-the-top than the image of an evil sorcerer standing atop the heads of enemies conjuring the malevolent powers of the universe, but in the end probably much more believable.