Is there any book for C-dac preparation having mock test paper or previous year question papers???
You can go through below books for your preparation
Section A
Quantitative Aptitude & Reasoning
R. S. Aggrawal
Section B
Data Communication & Networking
CompTIA Network+ Study Guide (Todd Lammle)
Data communication and networking (Forouzan)
C Programming
Let Us C (Yashavant Kanetkar)
C++ OOP balguruswamy
Operating Systems
Operating System Principles (Silberschatz, Galvin, Gagne)
Section C
Computer Architecture
Computer Organization & Architecture (William Stallings)
Digital Electronics
Digital Design (Morris Mano)
Modern Digital Electronics (R. P. Jain)
Microprocessors
Microprocessor Architecture, Programming & Applications
with 8085 (Ramesh Gaonkar)
The Intel Microprocessor (Barry Brey