Hi

You need to choose the code 03

This is because,

Though you  have completed your btech engineering, your highest qualification with all the three subjects i. e physics chemistry and Biology remains your PUC and for puc, one needs to choose code 3.

While those who have completed bsc with at least any two out of physics,  chemistry and Biology in their bsc need to select code 6.

Here's a short brief of Neet codes :-

Code 1 :- code 1 is for all those students who are going to appear for their 12th board examination in 2021 with physics, chemistry, biology and English.

Code 2 :- code 2 is for all those who have passed their 10+2 in the year 2020 or before with physics, chemistry, biology and English

Code 3 :- code 3 says it is for those passed their intermediate / pre- degree examination or pre university (  Puc)  in with physics, chemistry, biology and English ,your physics, chemistry and biology should also contain practical exam.

Code 4 :- pre - medical degree with Physics, chemistry and biology.

Code 5 :- code 5 is for all those who are doing BSc and has all the three of Physics, chemistry and biology in their graduation.

Code 6 :- code 6 is for all those students who have passed  BSc  with at least any two of following subjects :-

-) Physics,

-)chemistry ,

-)biology

Code 7 :- code 7 is for those who have passed their examination from foreign board which is equivalent of Indian 10+2 board.

For more visit

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

Thank you