Hi Aspirant!

You can write only biology from NIOS board. And once you get your marksheet, then you can write NEET 2022 exam under NEET Code 02. Also, there is no age limit on writing NEET exam, so you can take your time to qualify the 10+2 biology. The NEET code 02 says that, " Aspirants who have passed 10+2 from the National Institute of Open Schooling (NIOS) or state open school, as a private candidate from state boards; with Biology/Biotechnology as an additional subject can apply under NEET qualification code 2. "

To learn more about NEET codes, visit here:

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

Thankyou!