Hello,

Apart from being well acquainted with JEE Main Syllabus, it's good to know about Important Topics as well mentioned below-

For Physics

Magnetics-One of the topic from which maximum questions are asked in the question paper.

Optics-It is a relatively easy topic to study.

Modern Physics-It is one of the important and scoring topics for both JEE Main and JEE Advanced. Also, candidates must check sub-topics such as radioactive decay of substances, nuclear fission and fusion, dual nature of matter and X-rays in detail.

Electromagnetic Induction and AC- Generally, numerical problems are asked from this topic.

Oscillation and Waves-Must study this topic in detail.

Electrostatics- According to the previous year trend, this is the most scoring topic as almost four questions are asked from it every year in.

Current Electricity- Another important topic which candidates need to cover. Ohm’s law, colour code for resistors etc are asked from this.

For Chemistry

Organic Chemistry- Purification and Characterisation of Organic Compounds, Some Basic Principles of Organic Chemistry, Hydrocarbons, Organic Compounds Containing Oxygen, Organic Compounds Containing Nitrogen, BioMolecules etc.

Physical Chemistry- Some Basic concepts in Chemistry, Atomic Structure, States of Matter, Chemical Bonding and Molecular Structure, Surface Chemistry, Chemical Thermodynamics, Equilibrium, Chemical Kinetics, and Redox Reactions and Electrochemistry.

Inorganic Chemistry- Classification of Elements and Periodicity in Properties, General Principles and Process of Isolation of Metals, Hydrogen, s - Block Elements (Alkali and Alkaline Earth Metals), Co-ordination Compounds, Environmental Chemistry to name few.

For Mathematics

Permutations & Combinations

Definite Integration

Quadratic Equation

Conic Section

Differential Equation

Probability

Determinants

Application of Derivatives

Vector & 3D Geometry

Complex Numbers

Coordinate Geometry; Matrices in Algebra: Circle, Parabola, Hyperbola in Coordinate Geometry

Functions, limits, Continuity & Differentiability

Sequences engineers

Calculus; Definite Integral in Calculus

In addition to important topics for exam, you can also go through JEE Mains question paper with their answer which will be useful in your preparation process-

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

NEET/AIIMS for atleast all medical tests

Hello,

Your question isn't complete, you haven't mention whether you're asking this question in reference to 11 or 12th Standard or for any entrance exam, in case it's for JEE Mains, I've mentioned below-

In order to know which topics to skip, it's good to be well acquainted with important topics, it'll give you a fair idea about what's important and what's not-

For physics, the important topics are as follows-

Circular Motion, Center of Mass and Collisions, Communications Systems, Kinematics, Laws of Motion, Rotation, Electrostatics, Current Electricity and Capacitors, Magnetic Effects of Current and Magnetism, Electromagnetic Induction and Alternating Current, Bohr's Atomic Model, Waves  and Sounds,Units and Measurements, Work Energy and Power, Fluids, Nuclear Physics and X-Rays, Heat Transfer, Gravitation, Wave Optics, Ray optics, heat and thermodynamics, photoelectric effect, semiconductors, oscillations, electromagnetic waves.

Hello,

Following points will be really helpful if you try to work on it.

• Break the material down into small pieces.

It’s easier to process and remember information if you break it up into bite-sized chunks. Instead of trying to memorize an entire chapter of your textbook, focus on one short section or key piece of information at a time.

• Switch between different topics. It can be helpful to alternate between studying different subjects, so that your brain compartmentalizes the information more effectively. Switching between topics that are very different from each other can help keep your brain from getting bogged down with trying to remember too much about one subject (or 2 very similar subjects) at once. Additionally, switching between topics will help you avoid getting burned out on any one topic.
• Take notes.

As you’re listening in class or reading your text, write down important pieces of information. Don’t write down every word you hear or read. Instead, summarize key concepts. This will force your brain to process the information and condense it to its most important elements.

• Take breaks.

If you try to force yourself to study for too long in one sitting, you’ll soon start to nod off, or find your mind wandering. To make your studying more manageable and effective, try studying for an hour at a time. Take 5-15 minute breaks between study sessions to snack, stretch your legs, or put your head down for a quick catnap.

• Sleep on it.

Most people need 7-9 hours of sleep every night to be at their best. Getting enough sleep not only gives you energy and helps you concentrate, but it can also help you learn and remember. Your brain processes new information while you sleep, so you may find that you understand those difficult concepts better after a quick nap or a good night’s rest

NCERT : Always prioritize this! NCERT books are the primary reference books for all higher secondary subjects by the Central Board for Secondary Education. NCERT books cover 90% of NEET / AIIMS / JIPMER Chemistry syllabus accurately.

FOR PHYSICS:

1. Concepts of Physics Vol I and II by H.C.Verma -

Concepts are extensive, logical and engaging.Best pick for beginners to have a complete grasp on the subject.

Suggested Topics: Mechanics, Electrostatics, Optics, Modern Physics, Heat and waves.

2. Arihant’s Objective Physics for NEET, by D.C.Pandey -

Several reference examples.Systematic pattern of questions i.e. concepts arranged in increasing level of difficulty.Separate section called Entrance Corner which focuses on question patterns specially for competitive exams

3. MTG’s Objective NCERT at your fingertips for NEET, by Prof Satya Prakash Arya-

Various Mcqs. All the formulas are consolidated in one place which makes revision easier.Both 11th and 12th class topics provided chapter wise, based on NCERT - hence good for strengthening foundation.

4. Concepts of Physics for CBSE PMT, by Agarwal-

One of the most popular books for medical entrance exams as it caters to nearly all types of students.Has numerous questions of the same difficulty level as NEET.Also contains questions of different difficulty levels, based on other medical exams.

FOR CHEMISTRY-

1. Physical Chemistry, by O.P.Tandon

Well illustrated theory with numerical examples.
The summary after every chapter is structured to be very helpful.

Suggested Topics: Electrochemistry, Thermodynamics (Energetics) Chemical Kinetics, Thermochemistry.

2. MTG’s Objective NCERT @ your fingertips (Chemistry)

Chapter wise multiple choice questions (> 100 per chapter) for practice

Equipped with prep-meter to gauge progress.Best pick for quick and easy revision.HOT (most probable questions) Mcqs and model questions to make sure you don’t miss the most important concepts.Has diagram based questions which is a rarity in Medical Entrance prep books.

3. Concise Inorganic Chemistry, by J.D.Lee, Oxford

Theoretical concepts with elucidated reasoning.All concepts from basics to elaborate are explained in detail

Suggested topics: Preparation and Properties of Compounds, Ores and Minerals, Transition Elements.

4. Organic Chemistry, O.P.Tandon

Contains Multiple choice questions, matching type questions and assertion reason type questions.Exercise problems are provided with hints to improve understanding

FOR BIOLOGY:

NCERT books are widely used for biology. It is possible to score 300+ in biology by mastering NCERT books.

1. Trueman’s Elementary biology Vol I & II, by K.N.Bhatia and M.P.Tyagi

Very detailed,covers basics extensively and easily understandable

2. MTG’s Objective NCERT @ your fingertips (Biology)

Challenging questions explained to cater to average understanding.

Optimized for Self preparation

3. Dinesh Objective Biology

Published with insights from 27 years of medical entrance question papers.

The new edition includes a section called ‘Glance’ which is useful for a quick revision.Available with a booklet containing question papers from 2004 - 2016 (AIPMT and NEET)

I am no expert in NEET preparation, I just shared this information from Exambazaar here as I thought it would be helpful for you. You can visit Exambazaar to get more on your examination ! They provide all you look during your exam preparation. Just google - NEET preparation Exambazaar.

ALL THE BEST.