Hy,

The NCERT books are sufficient to prepare for 12th board exam. However, you must also refer the 12th standard as well in order to get good marks in 12th board .

The model Question paper is the best study material for the students. They are prepared, as the same format as the Bihar board previous year question paper 12th. They can gain complete knowledge about the question paper pattern for the upcoming intermediate examination.

Hopes this helps.

Wish you luck