dear pratap,

Here I am describing the all qualification code in a simple way -

code 01.  -This code is for the students who are appearing the 12th in 2020 and having subjects physics, chemistry , biology and English as a compulsory subjects.

code 02.  -This code is for the students who have passed the 12th standard form CBSC/ ISC and not taken addmission anywhere  (dropper or freshers ).

code 03 .  -This code is for the students who have passed their 12th from any state board(like up board, jac board, Karnataka board etc) with Physics, chemistry, biology /biotechnology and English as a compulsory subjects. (dropper or freshers ).

code 04.  -This code is for the students who have taken addmission in any pre medical or pre professional exam with Physics, chemistry, biology and English      after 12th .(example -nursing, pharma etc)

code 05.  -This code for first year students of Bsc with Physics, chemistry, biology /biotechnology. Also in 12th the student taken physics, chemistry, biology / biotechnology and English as a compulsory subjects.

Bsc second year students can fill code 05

code 06. -This code is for the students who are Bsc passout with any two subjects physics, chemistry, biology (botany or zoology)/biotechnology .Also in 12th the student taken physics, chemistry, biology and English.

code 07. -This code is not for Indian students .this is only for NRI and overseas students who have passed 12th with Physics, chemistry, biology.

so in my opinion you should select code 02 because you have not taken addmission after 12th and your highest education qualification is still 12th standard.