The Aryan invaders swept into India in approximately 1500-1700 BC and established the hallmark Indo-European tradition of the caste system, worshiped Indra as their highest God. Historians have long thought Indra to be equivalent to the Norse Thor.
https://en.m.wikipedia.org/wiki/Indo-Aryan_migration
https://en.m.wikipedia.org/wiki/Indo-Aryan_migration