Hello Souvik,

Best books for preparation :
MECHANICS
H.C. Verma
Resnick and Halliday
I.E. Irodov
OPTICS 
H.C. Verma
HEAT AND WAVES 
H.C. Verma
Resnick and Halliday
ELECRICITY AND MAGNETISM 
Resnick and Halliday
R.J. Smith  Circuits devices and systems
I.E. Irodov
MODERN PHYSICS
H.C. Verma
I.E. Irodov
Chemistry:
GENERAL CHEMISTRY
J.D. Lee
O.P. Aggarwal
R.C.Mukerjee
ORGANIC CHEMISTRY
NCERT Inorganic Chemistry
J.D. Lee Concise Inorganic Chemistry
O.P. Aggarwal
Mathematics:
ALGEBRA
Hall and Knight  High school mathematics
M.L. Khanna
CALCULUS and ANALYTIC GEOMETRY
G.N.Berman
Thomas and Finney  Calculus and analytic geometry
Loney  Coordinate geometry
M.L. Khanna
I.A.Maron
VECTORS
M.L. Khanna