Hello Arun Kumar Maurya,

According to jee mains syllabus we need to prepare for Physics, Chemistry and Mathematics. And preparing once check the weightage for every topic,this will help you to get high marks.

Mathematics syllabus :-Sets, relations and functions ,Complex numbers and quadratic equations ,Matrices and determinants ,Permutations and combinations ,Mathematical induction ,Binomial theorem and its simple applications ,Sequences and series ,Limit, continuity and differentiability ,Integral calculus ,Differential equations ,Co-ordinate geometry ,Three dimensional geometry ,Vector algebra ,Statistics and probability ,Trigonometry and Mathematical reasoning .

Physics syllabus:- Physics And Measurement ,Kinematics , Laws Of Motion , Work, Energy And Power ,Rotational Motion ,Gravitation ,Properties Of Solids And Liquids ,Thermodynamics ,Kinetic Theory Of Gases ,Oscillations And Waves ,Electrostatics ,Currrent Electricity ,Magnetic Effects Of Current And Magnetism ,Electromagnetic Induction And Alternating Currents ,Electromagnetic Waves , Optics , Dual Nature Of Matter And radiation , Atoms And Nuclei ,Electronic Devices and Communication Systems .

Chemistry syllabus:- Some Basic Concepts In Chemistry ,States Of Matter ,Atomic Structure ,Chemical Bonding And Molecular Strucure ,Chemical Thermodynamics ,Solutions , Equilibrium , Redox Reactions And Electrochemistry ,Chemical Kinetics  ,Surface Chemistry ,Classificaton Of Elements And Periodicity In Properties ,General Principles And Processes Of Isolation Of Metals ,Hydrogen ,S – Block Elements (Alkali And Alkaline Earth Metals) , P – Block Elements ,D – And F – BLOCK ELEMENTS ,Co-Ordination Compounds ,Environmental Chemistry ,Purification And Characterisation Of Organic Compounds ,Some Basic Principles Of Organic Chemistry ,Hydrocarbons ,Organic Compounds Containing Halogens ,Organic Compounds Containing Oxygen ,Alcohols, Phenols And Ethers ,Carboxylic Acids ,Organic Compounds Containing Nitrogen ,Polymers ,Biomolecules ,Chemistry in Everyday Life ,PRINCIPLES RELATED TO PRACTICAL CHEMISTRY and Chemical principles involved in the following experiments.

Hope this you..

Hi Arun!

Here is the syllabus of JEE MAINS 2020:

For Mathematics:

• Sets, Relations, Functions
• Complex Number and Quadratic Equations
• Matrices & Determinants
• Permutation & Combination
• Mathematical Induction
• Binomial Theorem
• Sequencers & Series
• Limit, Continuity & Differentiability
• Integral Calculus
• Differential Equations
• Coordinate Geometry
• Three Dimensional Geometry
• Vector Algebra
• Statistics & Probability
• Trigonometry
• Mathematical Reasoning

For Physics:

• Physics & Measurement
• Kinematics
• Laws of motion
• Work, Energy & Power
• Rotational Motion
• Gravitation
• Properties of Solids and Liquids
• Thermodynamics
• Kinetic Theory of Gases
• Oscillations & Waves
• Electrostatics
• Current Electricity
• Magnetic Effects of Current & Magnetism
• Electromagnetic Induction and Alternating Currents
• Electromagnetic Waves
• Optics

For Chemistry:

• Basic Concepts of Chemistry
• States of Matter
• Atomic Structure
• Chemical Bonding & Molecular Structure
• Chemical Thermodynamics
• Solution
• Equilibrium
• Redox Reactions and Electrochemistry
• Chemical Kinetics
• Surface Chemistry
• Hydrogen
• Block Elements
• Organic Compounds Containing Halogens
• Organic Compounds Containing Nitrogen
• D- and -f Block Elements
• Environmental Chemistry

Check this link for clarification: https://engineering.careers360.com/articles/jee-main-syllabus

Hope this helps.

ALL THE BEST!