The Ministry of Social Justice and Empowerment is a Government of India ministry. It is responsible for welfare, social justice, and empowerment of disadvantaged and marginalised sections of society, including scheduled castes (SC), Other Backward Classes (OBC), the disabled, the elderly, and the victims of drug abuse. The Ministry of Tribal Affairs is responsible for the welfare of scheduled tribes (ST).The Minister of Social Justice and Empowerment holds cabinet rank as a member of the Council of Ministers. The current minister is Thawar Chand Gehlot.
Competent Authority for Issue of Certificate to SC/ST/OBC/PC is District Magistrate/ Addl. Distt. Magistrate/ Collector/ Deputy Commissioner/ Addl. Dy. Commissioner/ Dy. Collector/ First Class Stipendiary Magistrate/Sub- Division Magistrate / Taluka Magistrate/ Executive Magistrate/ Extra Assistant Commissioner/ Chief Presidency Magistrate/ Additional Chief Presidency Magistrate/Presidency Magistrate/ Revenue Officer not below the rank of Tahsildar/ Sub Divisional Officer of the area where the candidate and/ or his/ her family normally resides.
check below the state wise list of SC,ST and OBC castes.
hope this helps!