Which country provides preferential treatment to those at the bottom of their traditional caste system?

The country that provides preferential treatment to those at the bottom of their traditional caste system is: India

In India's traditional caste system, there are 4 stratification of social class.

The Shudra is the lowest which consist of farmers, Vaishya is the third which consist of merchants and artist, Kshatriya is the second which consist of warriors, and Brahman is the highest which consist of nobles and religious leaders