There is no lying, Souren. Only previous question papers do not help. Because over the past 15 years, the syllabus must have changes atleast once or twice. By only sticking to previous question papers, you are confining your preparation to a specific portion leaving the rest. Because it is not necessary that all the syllabus needs to be asked in the exam. Now NCERT books are the ideal books for preparation because that's the recommended book ensemble for NEET preparation. Apart from that there are few books in the market too. To help you with your NEET preparation, we have NEET Knockout packages that you can check at: https://learn.careers360.com/knockout-neet-may/. To help you during admission and counselling, we have https://www.careers360.com/mbbs-companion.