Dear aspirant,

Wherever you are staying join the renowned coaching institute there because teachers in every coaching institute will teach you the same stuff. There is no rocket science in it.

It's just a myth that everyone joins kota and clear JEE. It's nothing like that if you would join kota only then you can clear it off.

Regarding giving jee in 12th , well you can give it a try for checking the pattern. Your actual attempt would be after you clear your 12th.