Ravi
Optimism is the key to success. Be positive. Go through the important formulae and concepts only as you don’t have time topractice the questions. You can try attempting some mock papers but only after getting through with the formulae and concepts. Considering you have not prepared for the IIT JEE throughout the year prior to the exam, I am assuming that you would have been concentrating on the Board Exams. Revise those concepts forst as they will not take much time to be covered, gradually move towards advanced concepts. In the exam, target the sections you are most comfortable with first and for the longest duration. Prioritise your subjects, topics and sub topics according to their weightage in the previous year papers.
All the best