You will be considered a dropper in B.Sc if you have taken the TC. But in your case, you are just not appearing for the exams and so on paper though your highest qualification is 10+2, as you have enrolled in 1st year of B.Sc, your code will be 05. 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.