Hi there

Best Books for GATE Computer Science.

• An Introduction to Formal Languages and Automata, Peter Linz
• Discrete Mathematics and Its Applications, Kenneth Rosen
• Introduction to Algorithms, C.L.R.S
• Database Systems, Elmasri & Navathe
• Computer System Architecture, Morris Mano
• The C Programming Language, Dennis Ritchie
• Data Communications and Networking, Forouzan
• Operating System Concepts, Galvin
• Data Structures Using C, Tenenbaum
• Compilers : Principles,Techniques & Tools, Ullman
• Modern Digital Electronics, R. P. Jain

Hope this helps. Good luck!