This is a common question many people ask.
Exam preparation is different from studying for knowledge. So, first of all, you should get the clarity on what is it that you want. Are you looking to enhance your knowledge and acquire new skills? Or, do you want to invest your time in getting a good GATE score? From the context of your question, I believe your objective is to do the latter.
Exam preparation requires you to acquire aptitude. Aptitude comes by investing time in thinking and practice. So, my first advice would be to value depth instead of breadth. Take few topics which are easy to score and do your best to solve as many problems as you can. You should be confident that if a question comes from this topic, you will certainly score it. Do not run behind covering syllabus.
My second advice would be to be conscious about the illusion of knowledge. Often, it seems that we understood a concept. Understanding a concept and solving a problem related to that concept are at different levels of aptitude. So, do not stop if you think you understood. Spend time in quality thinking and problem solving. One way to evaluate whether you have the aptitude is to solve past year problems on your own. So, mark few problems for testing and few problems for training.
My third and most important bit of advice is to hone your ability to recall. This sounds trivial. But, many people will agree that they knew it but had a black out during the exam. Their brain just could not recall anything. One way to do this is to practice recall. To be specific, everyday, spend 30 minutes recalling what you did before. Some call it revision. Do not look at the notes. Try to recall page by page what you wrote before. Recall the ideas. Recall some interesting problems.
CS is a vast subject. Too many topics and too many ideas to master. You may not get enough time to rock. Do not feel pressurized. Give importance to your job. If there is further time left, hopefully these tips will help you. Remember, if you are not having fun, you are not doing it the right way. This applies to learning and preparing for GATE too. Cheers and good luck!
