Dear Sheeza,

Students who want to focus only on entrance preparation and do not want to attend regular school due to time constraint, opt for a dummy school where the candidate needs to only go once a week but gets full attendance. It is encouraged more by the coaching industry. It is advisable to best avoid such a route as the student misses out on learning the regular syllabus of class 11 and 12th and also on practicals. 
Open school concept started with the idea that education should reach far and wide to remote areas too where there is a lack of proper school. However many students who want to prepare for entrances opt for NIOS as one doesn't need to attend a school regularly. Despite being established for distance education, NIOS provides a formal and regular secondary and Senior Secondary program equivalent to CBSE. This is a better and advisable option if you want to focus on entrance exams completely. 
Again NEET, the entrance for medical schools in India is in the process to debar students of NIOS board. So if you want to pursue MBBS make sure you opt for a regular CBSE school.

I hope this will clear all your doubts.

Good luck.

Hello Candidate,
I would suggest attending a regular school but you have to give 5-6 hour for your boards+IIT jee preparations.
Here are some rules you need to follow : Study chapters which carries more marks
Learn easy tricks to solve equations
Learns the topics in a deep way
solve previous years question papers
Take your NCERT books very seriously.
Concentrate on your studies and prepare well.
All the best :)

Hello
In this condition better to study the ncert books clearly by your own study and later on some of the reference books like physics h c verma and chemistry O p tandon 
I hope you understood
Good luck

Hello,
You should do regular schooling and strengthen your basic concepts if you want to crack any entrance exam. Make sure to study class 11th books also to under to understand the concepts which will help you in entrance exams.
Good luck.