Dear aspirant,

I'm glad that you want to prepare for JEE Mains and want to give most of your time of Class 11 and Class 12 towards JEE. Unfortunately though, you cannot take admission in a non-attending school or "dummy" school officially through CBSE. Many schools in Kota allow this kind of candidates but this has not been encouraged by CBSE. If you wish to get enrolled in such school you will have to do some research on schools around your area and see if they take admissions this way.

Hope this helps!

Good Luck!