Hi dipika

CDAC is an easy exam to crack if planned properly. Your basic concepts should be clear.
Your question is about section B. Right?
Ok so here i am providing the whole syllabus along with paper pattern to help you out.

See dipika there are total 50 questions from C Programming,Data Structure,Operating System and OOPs. Go through C Programming in depth and basic of O.S,OOPs,and D.S.

C Programming:

Topics:Declaration & Definition,Loop,Array,String & Structure

OOPs:Clear your basic OOPs concept and practice question as much you can

Topic:Class&Object,Access modifier,Inheritance,Polymorphism,Encapsulation.



Data Structure:

Topics: Sorting,Searching,Array & Linked List.

Operating System:

Topic: Types of operating system,CPU scheduling,Memory managements,Virtual memory,Paging.

Firstly find out your strong areas and weak areas .Based on time and strength work on it .
Focus more in c language and networking part, most of the question are from it .

Work hard and best of luck.