Hi Satya. For JEE Advanced, nearly 4-5 hours should be spent daily. Since, you are already spending 6 hours in school, and you need time for self study, you should make a proper schedule and work accordingly. Also, you should solve mock tests on alternate days and solve remaing on weekends. Try covering most of your syllabus on saturdays and sundays, so that you don't feel a pressure on yourself. All the best!

Hii satya Prakash,here is the solution to your problem as you are a school going student self study should be an important part of your curriculum,so for that should find a coaching where you will spend time not more than 3hours by doing this you will get time for your self study too.

Good luck