The Number of seats available in JCECE for SC candidates in Diploma courses are mentioned in the Prospectus , and this is clearly mentioned on the official website of JCECE Board. Therefore you have to purchase the Prospectus from the polytechnic college centre mentioned by the Board.

You should again read the page carefully of the Official website, which is as follows -

jceceb.jharkhand.gov.in/examination_detail/vitiece.aspx