Hi there.

If you are a private candidate who already has a Class XII Boards Marksheet then your code should be 02. If you have appeared in Class XII Boards examination this year and if your results aren't declared yet i.e. if you are still awaiting your results then your code should be 01.

For more relevant information kindly refer to the following link:

https://medicine.careers360.com/articles/neet-2018-what-nios-students-and-private-candidates-should-know

Hope this helps.