Hello Aspirant,

As per the latest announcement made by our Hon'ble Education Minister Mr. Ramesh Pokhariyal Nishank, the JEE-Main 2021 and NEET 2021 will be conducted on the basis of revised syllabus of CBSE so there is no need to study the reduced/deleted topics but this not for JEE-Advance 2021 so the revised syllabus by CBSE is described below :-

@Mathematics

Class 11th :-

Sets and functions

Algebra

Statistics and probability

Co-ordinate geometry

Calculus

Class 12th :-

Relations and Functions

Algebra

Claculus

Vector algebra and three-dimensional Geometry

Linear Programming

Probability

For detailed syllabus kindly check out the PDF published by CBSE :-

http://cbseacademic.nic.in/web_material/CurriculumMain21/revisedsyllabi/SrSecondary/REVISEDMathematics_Sr.Sec_2020-21.pdf

@Physics

Class 11th :-

Physics and measurement

Rotational motion

Thermodynamics

Kinematics

Work, energy and power

Properties of solids and liquids

Gravitation

Laws of motion

Oscillations and waves

Kinetic theory of gases

Class 12th :-

Current electricity

Electromagnetic induction and alternating currents

Magnetic effects of current and magnetism

Optics

Electromagnetic waves

Atoms and nuclei

Electrostatics

Electronic Devices

Dual nature of matter and radiation

+Experimental skills

For detailed syllabus kindly check out the PDF published by CBSE :-

http://cbseacademic.nic.in/web_material/CurriculumMain21/revisedsyllabi/SrSecondary/REVISEDPhysics_2020-21.pdf

@Chemistry

Class 11th :-

Some Basic Concepts of Chemistry

Structure of Atom

Classification of Elements and Periodicity in Properties

Chemical Bonding and Molecular Structure

States of Matter: Gases and Liquids

Chemical Thermodynamics

Equilibrium

Redox Reactions

Hydrogen

s-Block Elements

Some p -Block Elements

Organic Chemistry: Some basic Principles and Techniques

Hydrocarbons

Class 12th :-

Solid State

Solutions

Electrochemistry

Chemical Kinetics

Surface Chemistry

p -Block Elements

d and f -Block Elements

Coordination Compounds

Haloalkanes and Haloarenes

Alcohols, Phenols and Ethers

Aldehydes, Ketones and Carboxylic Acids

Amines

Biomolecules

+Experimental skills

For detailed syllabus kindly check out the PDF published by CBSE :-

http://cbseacademic.nic.in/web_material/CurriculumMain21/revisedsyllabi/SrSecondary/REVISEDChemistry_2020-21.pdf

For JEE-Advance 2021 syllabus kindly check out the link given below :-

https://engineering.careers360.com/articles/jee-advanced-syllabus

I hope this information helps you.

Good Luck!!