From the 14th to the 16th C, the Empire of Vijayanagara was the dominant power in South India. It provided a strong defence against the encroaching Deccan sultanates and established relatively centralised rule in South India.
However, at the Battle of Talikota in 1565, the Vijayanagaran army suffered unprecedented casualties against an (also unprecedented) united army of the Deccan sultanates. The victory has been attributed to the sultanate's more effective use of cannon.
More importantly, the Maharaja, Rama Raya was captured and beheaded. As a result, the retreating Vijayanagari army had no effective central leadership, allowing the Sultanates to seize the initiative and sack the capital, Vijayanagar. Though Vijayanagara survived for a century more, with the maharajas ruling from another capital, the empire slowly fell apart into vassal kingdoms which very soon became vassals in name only.
Where can we go with South India if we avoid Talikota? The Portuguese already have their colony in Goa which means we have potential for European influence.