Introduction:
Dr. B.R. Ambedkar was a prominent champion of the oppressed and depressed in India. He dedicated his life to fighting against social discrimination, inequality, and injustice faced by the marginalized sections of society. As the architect of the Indian Constitution, he played a pivotal role in ensuring the rights and upliftment of the oppressed communities.

Key Contributions:

1. Advocate for Dalit Rights:
Dr. Ambedkar belonged to the Dalit community, formerly known as untouchables. He tirelessly fought for their rights and worked towards eradicating the social evils of untouchability and caste-based discrimination. He strongly believed in equality and actively campaigned for the social integration of Dalits into mainstream society.

2. Drafting the Indian Constitution:
Dr. Ambedkar was appointed as the chairman of the Constitution Drafting Committee. His extensive knowledge of law, social justice, and equality were instrumental in shaping the foundational document of independent India. The Constitution included provisions to safeguard the rights and interests of the marginalized communities, ensuring their political representation and protection from discrimination.

3. Struggles against Discrimination:
Throughout his life, Ambedkar fought against various discriminatory practices prevalent in Indian society. He led movements against social evils such as untouchability, caste-based discrimination, and unequal treatment of women. He advocated for the right to education, access to public spaces, and eradication of social inequalities.

4. Reservation Policy:
Recognizing the historical disadvantages faced by marginalized communities, Dr. Ambedkar played a key role in implementing the reservation policy. This policy aimed at providing affirmative action in education, employment, and political representation for historically disadvantaged groups. It aimed to uplift the oppressed and depressed sections, ensuring their equal participation in the socio-economic and political spheres.

5. Women's Rights:
Dr. Ambedkar was a staunch advocate for women's rights and gender equality. He fought against the prevailing practices of child marriage, dowry, and unequal treatment of women. He emphasized the importance of education and empowerment of women for the overall progress of society.

Conclusion:
Dr. B.R. Ambedkar's contributions as a champion of the oppressed and depressed in India are immense. His relentless efforts to fight against social discrimination, drafting a progressive constitution, advocating for the rights of Dalits, and promoting gender equality have left an indelible mark on Indian society. His vision of an inclusive and egalitarian India continues to inspire generations to work towards a just and equitable society.