:::::::India in the sense you speak of relates to the Geographical region, the subcontinent. Technically according to your definition Pakistan, Sri Lanka, Bangladesh, and the Maldives would all be part of India in the Geographical sense. Politically India has only legally existed since the start of East India Company rule in the mid 1700's. The subcontinent has never been completely unified, there have always been competeing polities in the region. Even the Mugal Empire and the Mauryans were unable to rule the entire subcontinent at the hieght of their power as various minor states persisted in Southern India at the times of their empires. In any regard these large empires were broken up and destroyed as political entities, they have no liniage to the Republic of India at all, as the Roman Empire has no political succesion to the Republic of Italy today. See Succession of states for more information on the subject.