There is no official notification related to change in the syllabus of JEE Main 2018.  Exam date of offline exam is out that is 8th April, 2018.

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

Physics
Physics and measurement
Kinematics
Thermodynamics
Work, energy and power
Rotational motion
Gravitation
Laws of motion
Properties of solids and liquids
Electronic devices
Kinetic theory of gases
Oscillations and waves
Communication systems
Current electricity
Magnetic effects of current and magnetism
Electromagnetic induction and alternating currents
Electromagnetic waves
Optics
Dual nature of matter and radiation
Electrostatics
Atoms and nuclei

    Chemistry
    Physical Chemistry
    Some basic concepts in chemistry
    States of matter
    Atomic structure
    Chemical bonding and molecular structure
    Chemical thermodynamics
    Solutions
    Equilibrium
    Redox reactions and electrochemistry
    Chemical kinetics
    Surface chemistry

Organic Chemistry
Purification and characterisation of organic compounds

Hydrocarbons
Chemistry in everyday life
Principles related to practical chemistry
Organic compounds containing halogens
Organic compounds containing oxygen
Organic compounds containing nitrogen
Polymers
Some basic principles of organic chemistry
Biomolecules

Inorganic Chemistry
Classification of elements and periodicity in properties
Hydrogen
Block elements (alkali and alkaline earth metals)
Block elements group 13 to group 18 elements
D - and f - block elements
Co-ordination compounds
Environmental chemistry
General principles and processes of isolation of metals

 Good Luck!!