The caste system in India was used for what purpose

[paul linus]

One theory suggests with caste system people had no social mobility. The Aryans came to India and introduced the system to have control over local populations. Key roles were defined and people were assigned to the groups.

 

[Nil Thapliyal]

This is one theory but several scholars of the 20th century believe the Aryans didn't come from central Asia, but they originated in South Asia and thereafter spread to Europe.