Computer Science is one of the most coveted courses in the field of engineering. Here are some of the books name you can prefer for GATE preparation CSE branch.

Discrete Mathematics and Its Applications by Kenneth Rosen

Higher Engineering mathematics by B.S. Grewal

Advanced Engineering Mathematics by Erwin Kreyszig

The C Programming language by Dennis Richie

Classic Data Structures by Debasis Samanta

You can check the complete books by section wise with given below link.

GATE CSE Books

Good Luck!