Instead of choosing a random topic from the syllabus, you must break your preparation into sections. Sub-topics from each section should be selected and then strategy on clearing concepts must be made. Never leave any concepts doubtful or unsolved. Once done with the syllabus and concept clarity, you should move towards solving previous years papers. Give mock tests as much as possible. Time management is one more important thing you should look upon. Remember that practise will increase your efficiency. Read newspaper daily for current affairs and improve your vocabulary for this you cab read Norman Lewis. Two better books you can refer to-
Mass communication in India by Keval J Kumar and Success Master - Journalism and Mass communication entrance Examinations by Arihant Publications.