You can check the recommended study material below

Mathematics

Advanced Engineering Mathematics by Erwin Kreyszig

Gate Engineering Mathematics by MADE EASY

Network Theory

Engineering Circuit Analysis by Steven M. Durbin, Jack E. Kemmerly , William H. Hayt

Analog Electronics

Fundamentals of Microelectronics by BEHZAD RAZAVI (Must Read Recommended by Aditya)

GATE - Electronics & Communication (Analog Circuits Volume 5 Of 10) by R K Kanodia

Digital Electronics

Solved previous year questions from EC and IN streams

Signals and Systems

Signals And Systems (Schaum’s Outline Series) by H P HSU Signals & Systems by Alan V. Oppenheim

Communication Systems

Modern Digital and Analog Communication System by B P LATHI

Electrical and Electronic Measurements

A Course In Electrical And Electronic Measurements And Instrumentation by A K SAWHNEY

Control System

Automatic Control Systems by B C KUO

Process Control

Process Control: Modeling, Design, And Simulation by B. Wayne Bequette

Transducers

Introduction to Measurements and Instrumentation by ARUN K GHOSH

Good Luck!!