Hi

Although each and every chapter in the syllabus is important for the jee main but if you are at a shortage of time then these are some. of the most important chapters once should definitely complete before appearing for jee main.

Mathematics

• Calculus
  • Functions, Maxima and minima, Monotonocity, Definite Integration ,Area under the curve and Differential equations are the important ones.

• Algebra

  • PNC, Probability, Sequence and Series are the important chapters

• Coordinate Geometry

  • Circle, Parabola, Straight lines are the important topics.

• Trigonometry

  Recommended

physics

• Electrostatics
  • Capacitors
  • Current electricity are important topics

• Magnetism

  • Electromagnetic Induction
  • Faraday's and Lenz Law
• KTG & Thermodynamics
  • Carnot cycle
  • Conversion of graphs
  • Polytropic process

• Mechanics

  • RBD(around 2 questions)
  • Centre of mass
  • Motion in one and two dimensions
  • Work power and energy

Chemistry

For chemistry read NCERT thoroughly and it will suffice.

Goodluck.