Here I am giving you information about important Subjects that are Generally required in placement examination for various companies below :

Computer Science & Engineering (CSE),
IT
Digital Electronics & Microprocessor,
Operating System,
C,
Algorithm & Data structure,
Theory of Computation,
Compiler Design ,
Computer organization & Architecture,
DBMS,
Design and Analysis of Algorithm,
Computer Network,
Software Engineering

Civil
Building materials,
Solid mechanics, Structural analysis,
Design of steel structures,
Design of concrete and masonry structures,
Construction practice,
planning and management, Fluid mechanics,
open channel flow, pipe flow,
Hydraulic machines and hydropower,
Water resources engineering, Water supply engineering, Soil mechanics, Surveying, Transportation engineering

Electronics & Communication Engineering (ECE)
Networks,
Electronic Devices,
Analog Circuits,
Digital circuits,
Signals and Systems,
Control Systems,
Telecommunications, Electromagnetic

Mechanical Engineering
Thermodynamics,
Heat Transfer and Refrigeration and Air-conditioning,
Fluid Mechanics,
Fluid Machinery and Steam Generators,
Theory of machines, Machine design ,
Strength of materials,
Engineering materials,
Production engineering, Industrial engineering

Electrical Engineering (EE)
EM Theory, Electrical Materials ,
Network Theory,
Measurements and Instrumentation,
Control systems,
Electrical Machines,
Electrical Power systems,
Analog and digital electronics and circuits,
Microprocessors, Power electronics