Hello

You can check out the complete syllabus of JEE Mains from here and as given below-

The important topics for JEE Mains Exam is as follows-

Capacitance

Current Electricity

Electro Magnetic Field

Electro Magnetic induction

Calorimetry & Thermal Expansion

Heat Transfer

KTG & Thermodynamics

Chemical Bonding

p-block

Coordination Compounds-

Metallurgy

Hi Naresh, 

As far as I know the whole of plus 1 and plus 2 Physics, Chemistry and Mathematics syllabus is the syllabus for JEE MAIN. Still I will list down dome topics from each subject below for your better understanding:-

Physics – Waves & Sound, Geometrical Optics, Thermodynamics, Kinetic Theory of Gases, Rotational Dynamics, Dimensional Analysis, Gravitation & Electrostatics, Current Electricity & Heat Transfer, Electromagnetic Induction

Chemistry – Chemical bonding, Mole concept & the concept of equivalents, Redox reactions, Electrochemistry, Thermodynamics, Qualitative analysis, Chemical equilibrium in physical chemistry, Carbonyl Compounds & their derivatives in organic chemistry and Coordination chemistry.

Mathematics – Limits, Continuity and Differentiability, Application of derivatives, Definite integral in calculus, Circles and Family of Circles, Sequence and Series, Probability, vectors, Hyperbola in coordinate geometry, Functions, Quadratic equations and expressions, Complex numbers, Matrices, Parabola, Inverse Trigonometric Functions.

Hello aspirant, 

Jee main 2020 syllabus will be probably same as that of jee main 2019 syllabus. Some changes may occur but the overall content is almost same in all the years. For gate 2019 syllabus, go to

https://www.google.com/amp/s/engineering.careers360.com/articles/jee-main-syllabus/amp

Good luck