acoording to jee main 2008-2011
Most important topics for Maths are (In decreasing order of importance)
LIMIT, CONTINUITY AND DIFFERENTIABILITY [Marks 20]
CO-ORDINATE GEOMETRY [Marks 20]
INTEGRAL CALCULUS [Marks 12]
COMPLEX NUMBERS AND QUADRATIC EQUATIONS [Marks 8]
MATRICES AND DETERMINANTS [Marks 8]
PERMUTATIONS AND COMBINATIONS [Marks 8]
SEQUENCES AND SERIES [Marks 8]
THREE DIMENSIONAL GEOMETRY [Marks 8]
STATISTICS AND PROBABILITY [Marks 8]
TRIGONOMETRY [Marks 8]
BINOMIAL THEOREM AND ITS SIMPLE APPLICATIONS [Marks 4]
VECTOR ALGEBRA [Marks 4]
MATHEMATICAL REASONING [Marks 4]
SETS, RELATIONS AND FUNCTIONS [Marks 0]
MATHEMATICAL INDUCTION [Marks 0]
DIFFERENTIAL EQUATIONS [Marks 0]
Most important topics for Physics are (In decreasing order of importance)
ELECTROSTATICS [Marks 20]
OPTICS [Marks 12]
EXPERIMENTAL SKILLS [Marks 12]
PROPERTIES OF SOLIDS AND LIQUIDS [Marks 8]
OSCILLATIONS AND WAVES [Marks 8]
ELECTROMAGNETIC INDUCTION AND ALTERNATING CURRENTS [Marks 8]
ELECTRONIC DEVICES [Marks 8]
PHYSICS AND MEASUREMENT [Marks 4]
KINEMATICS [Marks 4]
WORK, ENERGY AND POWER [Marks 4]
ROTATIONAL MOTION [Marks 4]
GRAVITATION [Marks 4]
THERMODYNAMICS [Marks 4]
KINETIC THEORY OF GASES (Marks 4)
MAGNETIC EFFECTS OF CURRENT AND MAGNETISM[Marks 4]
ELECTROMAGNETIC WAVES [Marks 4]
DUAL NATURE OF MATTER AND RADIATION [Marks 4]
ATOMS AND NUCLEI [Marks 4]
LAWS OF MOTION [Marks 0]
CURRENT ELECTRICITY [Marks 0]
COMMUNICATION SYSTEM [Marks 0]

in chemistry if you are running short of time then emphasise on physical and inorganic.

thanks and regards
sunil kr
askIItian faculty