In eastern Bengal, Haridas Thakur’s Matua sect worked among Chandala cultivators.

Explanation:

In the 19th century, social reform movements emerged in India to challenge caste-based discrimination and promote equality. One such movement was led by Haridas Thakur in eastern Bengal.

Key Points:

• Matua Sect Formation: Haridas Thakur established the Matua sect, focusing on uplifting marginalized communities, particularly the Chandala cultivators, who were considered "untouchables" and faced severe social ostracism.
• Challenge to Caste System: The Matua sect questioned the legitimacy of Brahmanical texts that endorsed the caste hierarchy, advocating for a society based on equality and justice.
• Advocacy for Social Equality: By promoting inclusive spiritual practices and emphasizing the inherent worth of every individual, the Matua movement sought to dismantle caste-based prejudices and improve the socio-economic conditions of the Chandala community. 

Haridas Thakur's efforts through the Matua sect played a significant role in challenging caste-based discrimination in eastern Bengal, working directly with Chandala cultivators to promote social reform and equality.