Hello uday

To get good marks in NEET you need to study very hard,

As the competition in NEET is very high and also the numbers of applicants is increasing every year.so it's really very important to prepare correctly.

For NEET it will be good if you study all your NCERT thoroughly and as NCERT have a very simple and a good source to clear all the basic concepts in chemistry and physics. Study and practice numericals in physics and chemistry as much as you can,also buy mock test papers for practice.

As you will understand what are your weakness and how can you fix that.

You can also do a crash course if you can as the material provided by the coaching institutes are really useful.

And if you can't don't feel bad just study hard.

For weak memory

1. Always revise what you've studied periodically.
2. Meditate.
3. Eat healthy and green vegetables as much as you can.
4. Learn some memory sharpening techniques.they help a lot.