B.R. Ambedkar organised the dalits into the Depressed Classes Association.

Explanation:
B.R. Ambedkar, also known as Babasaheb Ambedkar, was a prominent leader and social reformer who dedicated his life to uplifting the oppressed and marginalized sections of society, particularly the Dalits or the untouchables. He played a significant role in organizing the Dalits and advocating for their rights.

Ambedkar's Efforts:
1. Founding the Depressed Classes Association: In 1930, B.R. Ambedkar founded the Depressed Classes Association, which aimed to address the social, economic, and political issues faced by the Dalits. The association provided a platform for the Dalits to voice their concerns and fight for their rights.

2. Mobilizing the Dalits: Ambedkar worked tirelessly to mobilize the Dalits and create awareness about their rights and the need for social reform. He organized various movements and campaigns to challenge the oppressive caste system and caste-based discrimination.

3. Focusing on Education: Ambedkar believed that education was crucial for the empowerment of the Dalits. He emphasized the importance of education in eradicating social inequalities and worked towards establishing educational institutions for the Dalits. He himself was highly educated, holding multiple degrees, including a doctorate from Columbia University.

4. Drafting the Indian Constitution: Ambedkar played a pivotal role in drafting the Indian Constitution. As the chairman of the drafting committee, he ensured that the Constitution included provisions to safeguard the rights and interests of the Dalits. These provisions included reservations in education, employment, and political representation for the socially disadvantaged sections of society.

5. Conversion to Buddhism: Ambedkar's efforts to uplift the Dalits extended beyond social and political reforms. He believed that the caste system was deeply ingrained in Hinduism and that the Dalits needed to escape its clutches. In 1956, he led a mass conversion ceremony where he and thousands of his followers embraced Buddhism as a means to escape caste-based discrimination.

Conclusion:
B.R. Ambedkar's tireless efforts and leadership were instrumental in organizing the Dalits into the Depressed Classes Association. Through his activism, social reforms, and contributions to the Indian Constitution, Ambedkar left a lasting impact on the Dalit community and the fight against caste-based discrimination. His legacy continues to inspire and guide movements for social justice and equality in India.