2,762 Indian genomes cover most regions, languages, tribes, castes. Most Indians descend from three ancestral sources: Iranian-related farmers, Eurasian Steppe pastoralists, South Asian hunter-gatherers. Iranian-related ancestry traces to Central Asia Neolithic cultures shared by Ancestral South Indians, North Indians, Austro-Asiatics, East Asian-related groups. India shifted to endogamy post-admixture, causing high homozygosity and identity-by-descent sharing. Indians carry 1-2% ancestry from archaic hominins including Neanderthals and Denisovans. Indian genomes yield 1.5 Gb (50%) of introgressing Neanderthal genome, highest recovery ever. Indian genomes yield 0.6 Gb (20%) of introgressing Denisovan genome. Indians show largest worldwide variation in Neanderthal ancestry. Indians have highest population-specific Neanderthal segments among global groups. Most Indian genetic variation stems from single Out-of-Africa migration 50,000 years ago. Minimal contributions from earlier migration waves into India.