The first two sentences of the Preface of a book titled "Aryan and Non-Aryan in India":

"The history and mechanisms of the convergence of ancient Aryan and non-Aryan cultures has been a subject of continuing fascination in many fields of Indology. The papers in this volume are the fruit of a conference on that topic held in December 1976 at the University of Michigan, Ann Arbor, under the auspices of the Center for South and Southeast Asia Studies....."

Aryan and Non-Aryan in India (Deshpande, et al.)

Additional information from Wikipedia:

"Indo-Aryan peoples refers to both the pastoralist Indo-European people migrating from Central Asia into South Asia in the second millennium BCE, introducing the Proto-Indo-Aryan language, as well as to contemporary Indo-European ethnolinguistic groups speaking modern Indo-Aryan languages, a subgroup of the Indo-European language family.

The introduction of the Indo-Aryan languages in the Indian subcontinent was the result of a migration of Indo-Aryan people from Central Asia into the northern Indian subcontinent (modern-day India, Nepal, Bhutan, Bangladesh, Pakistan and Sri Lanka). These migrations started approximately 1,800 BCE, after the invention of the war chariot, and also brought Indo-Aryan languages into the Levant and possibly Inner Asia.

The Proto-Indo-Iranians, from which the Indo-Aryans developed, are identified with the Sintashta culture (2100–1800 BCE), and the Andronovo culture, which flourished ca. 1800–1400 BCE in the steppes around the Aral sea, present-day Kazakhstan, Uzbekistan and Turkmenistan. The proto-Indo-Aryan split off around 1800–1600 BCE from the Iranians, moved south through the Bactria-Margiana Culture, south of the Andronovo culture, borrowing some of their distinctive religious beliefs and practices from the BMAC, and then migrated further south into the Levant and north-western India. The migration of the Indo-Aryans was part of the larger diffusion of Indo-European languages from the Proto-Indo-European homeland at the Pontic steppe which started in the 4th millennia BCE. The GGC, Cemetery H, Copper Hoard, OCP and PGW cultures are candidates for cultures associated with Indo-Aryans.

The Indo-Aryans were united by shared cultural norms and language, referred to as aryā, "noble." Diffusion of this culture and language took place by patron-client systems, which allowed for the absorption and acculturalisation of other groups into this culture, and explains the strong influence on other cultures with which it interacted."