Hello Aspirant,

See it is large difference between 25.6 percentile and 99 percentile but still if your concepts are clear then you can of course go for it. So If you are done with your syllabus of JEE-Main 2021 then solving Previous Year Questions, different Mock tests and sample papers is the best practice to get the thorough preparation of JEE-Main or any other competitive examination, so what I would recommend you is just solve one paper in a day in the fixed time of Three hours and don't go for next paper until you clear all your doubts of previous paper so the concepts will be cleared to you. You can download different previous year's question papers and sample papers of JEE-Main from the link given below :-

https://engineering.careers360.com/articles/jee-main-sample-papers

https://engineering.careers360.com/articles/jee-main-question-paper

You can also check out our JEE-Main Learner's program which  includes the full length Mock test series  and you check out this from the link given below :-

https://learn.careers360.com/knockout-jee-main-april/?product=27

NTA has also given the facility for mock test which you can give from the link given below :-

https://nta.ac.in/Quiz

As we know that now the aspirants are facing their last time preparation before JEE-Main examination so now the solving papers should be the main priority because at this point of time reading of full concepts and chapters won't be the wise strategy so just be focused on solving papers and some important chapters which have more weightage as compare to that of others and for your reference I have mentioned those chapters :-

@Physics

Modern Physics - 20 marks

Heat and Thermodynamics - 12 marks

Optics - 12 marks

Current Electricity - 12 marks

Electrostatics - 12 marks

Magnetics - 8 marks

@Chemistry

Transition Elements and Coordination Chemistry  -  12 marks

Periodic table and Representative Elements - 12 marks

Thermodynamics And Gaseous State- 8 marks

Atomic Structure - 8 marks

Chemical Bonding - 8 marks

Chemical And Ionic Equilibrium - 8 marks

@Mathematics

Coordinate Geometry  -  20 marks

Limits, Continuity and Differentiability - 12 marks

Integral Calculus - 12 marks

Complex numbers and Quadratic Equation - 8 marks

Matrices and Determinants - 8 marks

Statistics and Probability - 8 marks

Vector Algebra - 8 marks

For more detailed preparation tips for JEE-Main 2021 kindly check out the link given below :-

https://engineering.careers360.com/articles/jee-main-preparation-tips

I hope this information helps you.

Good Luck!!