Hii

Its not like that, CBSE and COBSE syllabus will be covered in the NCERT and also you can use the reference books for your preparation. Do not feel like you miss out something that will be asked in the paper. The paper is set after considering all the factors like which states has what syllabus, books and board. SO no body has to worry and just focus on your preparation.
I am providing links which you can use to know about the syllabus of NEET and best books after NCERT .
https://medicine.careers360.com/articles/neet-2019
https://medicine.careers360.com/articles/neet-syllabus
https://medicine.careers360.com/articles/best-books-for-neet

Thanks!!!