how many percentage of questions in neet 2020 will be from NCERT?

About 80-85% of the total questions came directly from NCERT

Hey aspirant;
Everything is from ncert. The maximum questions asked would be from ncert. The questions can be directly put forward or may be indirectly quoted from ncert. But it has to be from ncert. There would be around 97 to 98% of questions from ncert. Only 2 or 3 questions would not be from ncert. As far as biology is concerned all questions are from ncert except one or two which checks your interest level , for chemistry it's entirely ncert, the language and numericals might be twisted a bit and the reactions may be made further complex. For physics the numericals can or cannot be from ncert. But the formula and Theory behind them would be from ncert.
You can also expect certain lines directly quoted from ncert. So, it would be my personal advice to just memorize the whole books...
All the best. :)