If you are studying BDS and want to appear in NEET, your highest qualification will remain class 12th. Your qualification code is 02. That is because BDS doesn't have subjects like Physics, Chemistry, Biology/Biotechnology. Your highest qualification which has these subjects is class 12th and so your qualification code will be 02.

For more information about NEET code, you can refer:

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

Hope, it helps!