If you are clear with your goal that you want to be an Engineer and you want to study in the best college in India then for sure you should follow the non-schooling system. But I will suggest you should start preparation from 11th standard onwards rather than from 6th, 7th, 8th or 9th standard. why? Because School is something where you don't go just to study but you go there to learn many things which you can not learn from a book .
Advantage of Non-Schooling over Schooling
- You will get more time to build your problem-solving skill.
- You will be less tired and you will be more Productive. Because If you will manage both coachings and School your productivity will be low.
- You will be able to concentrate at one place and if you will join both you can not concentrate on one place. Because they will teach different chapter in School and they will teach different chapter in coaching. It would be difficult to handle