To score 200+ in JEE Main make sure your concepts are clear take NCERT help for that. To cover up your syllabus and focus on important topics you should make proper plan.
Focus on revision try to solve as many as MCQs for your practice. Try to solve previous year papers to understand the pattern and difficulty level of the exam.

You can also refer below books for your preparation-

PHYSICS

NCERT textbook and exemplar

Previous years JEE objective type question (single option)

MATHEMATICS

NCERT text book and exemplar

Co-ordinate geometry and trigonometry- S L Lorney

Calculus  I.A, Maron

Algebra- Hall & Knight + Bernard- child

Previous year IIT-JEE question bank

CHEMISTRY

NCERT text book and exemplar

Physical chemistry- P. Bahadur, N Awasthi, Atkins & RC Mukherjee

Organic chemistry- M.S. Chuahn, Jerry March I L Finar

Inorganic chemistry- JD Lee

Previous year JEE question bank

Below are the some important topics for your preparation-

Physics: You should have a fair understanding of Kinematics and Dynamics, and it is essential to be able to build a strong problem solving ability. Also, the Theory of Fields (Electromagnetism) is very important. But do not ignore Heat & thermodynamics, optics and modern Physics. They are easy and scoring also.

Chemistry : Physical Chemistry can fetch you good scores and hence, all the units under it must be done carefully. Students tend to neglect Inorganic Chemistry, but just a proper understanding of it can prove to be beneficial. General Organic Chemistry must be understood and memorized to score well in Organic Chemistry.

Mathematics : Calculus forms a base for almost every part of Mathematics. Other important and scoring topics are Determinants, Sequences, Permutation and Combination. The student must be able to relate the complex numbers with Coordinate Geometry and Vectors. Three Dimensional Geometryshould be practiced to get that additional or compensating score.