For the GDS (Grameen Dak Sevak) post, the category you should choose depends on the specific details of your SEBC (Socially and Educationally Backward Classes) certificate and the reservation policies applicable in your state or region. SEBC is generally equivalent to OBC (Other Backward Classes) in many states.

If your SEBC certificate is recognized as OBC in the context of central government jobs, you should choose the OBC category. If you also meet the criteria for EWS (Economically Weaker Section) and have an EWS certificate, you can choose the EWS category.

If you have both certificates and are eligible for both categories, you might prefer to choose the category where you have a better chance of selection based on the number of vacancies and competition