Raja, 97-98% of the questions are asked from NCERT books alone. The rest 2-3% are from other books. Assuming that you only study NCERT books, you should be able to answer 98% of the questions.You just need to be careful so as not to give incorrect answers. You get to save every point that you scored. Now what you will score depends on what you have learnt. So even if you go by NCERT books, your preparation level is what decides how much you score in the exam. But on a general note, if you follow NCERT books you will score 200 and above. We also have JEE Knockout packages to help you with your preparation: https://learn.careers360.com/knockout-jee-main-april/