This religion practices a social caste system.

Buddhism

Taoism

Islam

Hinduism

I believe the answer is Hinduism

It is Hinduism that practices a social caste system. The caste system is a social order which groups people into different sections of society depending on their birth. Some teachings within Hinduism promote the idea that we as human beings must accept that we are different from each other, and that as a result there are different roles in society that each of us should do.