Though you have completed until your B.Sc 2nd year, but because you have discontinued your Graduation, your highest educational qualification will remain your 12th . But again because you have completed your First year B.Sc successfully but not the entire Bachelor's programme, your code will be 05. Code 05 says that:

Anyone who has passed the first year of a bachelor's degree from a recognized university with Physics, Chemistry, BIology/Biotechnology inclusion of practical tests. Candidates should also verify that the first year exam qualified is a university-level exam and they have also qualified Class 12 qualifying examination with the said subjects at a level not less than a core course.

But had you not taken your TC, your code will be 02 because then though your highest educational qualification is 12th, you do not have your relevant B.Sc documents. But in your case because you have the TC after 2nd year, your code will be 05. Code 06 is for those who have completed their B.Sc and unfortunately you do not fall under that Category.