CBSE.
it depends what your preferences are . IIT MUMBAI is good . Think of long term what you want to do later MS / Specialization or MBA
IIT books are available in arihanth website. While i prefer to read them manually.
CBSE.
Study Hard.. and focus on concepts !!
Yes.
Clarify the question and I will answer it or message my board
you can get your score online or IIT-JEE control board sends u score card
IIT MBA is a very good option for Post Graduation after IIT.
You should atleast gain a rank better than 6000 to get in to the iit sciences.
You should get selected for IIT if you seek better knowledge and want to end up with fat salary.
You can get it online or through scorecard sent by examination board
It is not necessary to join foundation classes for IIT-JEE preparation. An IIT aspirant must study the ICSE curriculum and score 90+% thoroughly so that he is kind of accustomed to a heavy study routine. Foundation Classes, though certainly helpful, are not required at all. The student should religiously study for around 5-6 hours per day from Grade 11 in order to crack the IIT-JEE exam.