Those nomad Aryans invaded India 4500 years ago and started caste system to avoid mixing with dark skin indigenous people. Being nomads, some lost their way and ended up in Lithuania.
The Aryan “invasion” theory has been debunked.
The period when the Aryans moved to north India was well after the heyday of the Harappan civilization. It looks like climate change forced the proto-Dravidian speakers to move south to Southern India.
The caste system seems to have been developed by the Indo-Europeans while still a tribe in the Kuban - as witnessed by the separation of priestly, warrior etc. caste.