Hi there. 

Cracking NEET in 100 days which is around 2 months is like aiming to trek a Mountain without any preparation before hand. 

2 months is very less time if you haven't even touched your books. But, if you have been studying even a little here and there, you'll be able to score if nothing, but decently, if you study for 2 months diligently. 

First of all, be thorough with NCERT of Biology and Chemistry. 

Biology's NCERT is enough for preparation, and for inorganic chemistry as well. 

For Physical Chemistry try solving questions of previous years first and when you are done with those try sums from Vibrant Academy's Book of Physical Chemistry. For organic, keep learning the mechanisms and name reactions and solve PYQ. If you complete all this in 2 months it would be enough. 

For Physics, just read the summary of a chapter, make a formula chart and dive into the previous year questions. When you are done with those, start with DC Pandey and go for important chapters first like SHM, Mechanics etc. 

See, 2 months may and may not be enough for you depending on your intelligence, aptitude, passion and time management abilities. 

Moreover, check the link below for different weightage of chapters in NEET : 

Https://www.google.co.in/amp/s/medicine.careers360.com/articles/neet-chapter-wise-weightage-and-important-topics/amp

Hope this helps. 

Good luck!