Hay there,

Go for code 2.

Though you are pursuing a Engineering course or anything but your highest eligible degree will be considered that degree only which has Physics, Chemistry, Biology/Biotechnology as the core subjects. So in view of NEET eligibility you just year drop after 12th and as you said you have completed your 12th with Physics, Chemistry and Biology and Maths.

So according to this your highest qualification will be considered as 12th class in which you had Physics, Chemistry and Biology.

According to code 2, all the students who have passed class 12th in 2020 or in past year, then they come under code 2.

So you should fill code 2.

For more information about NEET codes, you can go through the link below.

https://medicine.careers360.com/articles/neet-qualification-codes

To know the process to apply for NEET, you can visit the link below.

https://medicine.careers360.com/articles/how-fill-neet-application-form

I hope this answer helps you.

All the very best!!