CBSE

You will have to pay attention to the following points for an effective JEE Mains and Advanced preparation in one year.
Hard work:
You have one year to master 2 years 11th and 12th course. You will have to study at least 6 hours in weekdays and 10 hours on weekends along with your school and coaching.
Determination:
There will be times when you would find it difficult to understand and manage things. Do not give up as that is the point where many aspirants give up and finally fail. Keep putting your best, even if you feel like you are not getting any output. Remember, hard work forever pays. Be clever Now you need not cover every topic of syllabus. Since you have only one year, just look up the topics once in the previous years JEE Advanced exams and observe the trend. Skip unimportant topics. Try to develop tricks to save time while solving questions. Keep calm and prepare
You will feel a lot of pressure from parents and colleagues who are better. But you need not panic. Never let your mind drown in any kind of pangs and fears. It will decrease your ability to learn and apply. You may practice meditation to develop your efficiency.
Best of luck.