Hey Harshit,

Make sure that you come up with all the concepts by preparing. To improve your verbal ability, you have to make full and hars effort, not just for a month prior to the exam, but throughout your school life. You can just add about a cent more of your existing vocabulary in that one last month.
Most importantly, make sure you have a clear mind before the exam. Give your best in those two hours. Don't make any guesses, as there is negative marking.