If a candidate wants to clear some subject as additional what is the procedure?

A candidate who has qualified for the grant of the Secondary School Certificate may appear on prescribed fee and form in any subsequent examination, in a subject or subjects not offered by him previously before taking higher Examination in the same Board or any other Board. Such a candidate shall, on passing in the relevant subject/s be granted a certificate to that effect i.e. additional subject/s. Moreover if the candidate appeared in more than one subject he/she must pass all the subjects. Provided that on qualifying an additional subject/s will not be allowed to improve the marks.