It’s not necessary but it is always advisable to do so. If you’re aiming to score high in your exam, you wouldn’t want to leave any room for mistakes. Making sure you complete the entire syllabus is one thing that will help you do so. The syllabus may seem difficult to understand but all it takes is time and practice. You can cover the entire syllabus by solving the previous year Computer Science question paper for CBSE Class 12 available on Vedantu and it's app.