SC/ST certificates must be issued by any of the following authorities within the respective local jurisdiction:

1. Deputy Collector of Land Revenue, Kolkata

2. Collector of Stamp Revenue, Kolkata

3. Metropolitan Magistrate, Kolkata

4. Additional Chief

5. Metropolitan Magistrate, Kolkata

6. Chief Metropolitan Magistrate, Kolkata

7. First Class Stipendiary Magistrate

8. Executive Magistrate

9. Sub-divisional Magistrate

10. Sub-divisional Officer

11. Deputy Collector

12. Additional District Magistrate Collector , i think this information is enough for you.  if you still have any doubt or query you can ASK IN  comment section.