Your code will be 05 because you need to be pursuing B.Sc in any of 2 subjects among Physics, Chemistry and Biology. Code 05 says: The first year of the three years’ degree course of a recognised University with Physics, Chemistry and Biology/Biotechnology including practical tests in these subjects provided the examination is a University Examination and candidate has passed the earlier qualifying examination with Physics, Chemistry, Biology/ Biotechnology with English at a level not less than a core course.