CBSE 12th

Hello Hridkamal, With your percentile, you can expect to get admission in very good B school. Just remember CAT is only one screening. You will have to go through some more and as you score, your chances will keep on improving.

Hi, You may follow this book on Amazon:
http://www.amazon.in/Crack-IIM-Indore-Entrance-Examination/dp/9332560153/ref=dp_ob_title_bk

Yes, you are eligible for scholarship in Amity for MBA.
The scholarship pattern for MBA is -
For 100% Scholarship
Eligibility - Students securing 93% aggregate and above ((excluding Physical Education/ Fine Arts / Performing Arts / vocational / non written subjects) in CBSE/ ICSE Board of Class XII and 80% in Graduation.
For 50% Scholarship
Eligibility - Students securing 90% aggregate and above (excluding Physical Education/ Fine Arts / Performing Arts / vocational / non written subjects) in CBSE/ ICSE Board of Class XII and 75% in Graduation.

You might not be eligible for BCA due to age restriction . For more details, check out the link below :
https://www.shiksha.com/it-software/course/bachelor-of-computer-applications-directorate-of-distance-education-Punjab-technical-university-Punjab-other-283883

You should definitely be a teacher. Pick a subject you are good in and pursue it. If you like explaining things and making others understand a topic, you are truly gifted. Please refer to the link provided below for a list of careers which you can pursue after class 12. Select the stream you want to pursue and pursue it with great conviction. Good Luck!
https://www.shiksha.com/careers

Some of the popular schools abroad for B.Arch are listed below.
1) New York Institute of Technology
2) University of Nottingham
3) Carnegie Mellon University (USA)
4) The University of Liverpool, UK
5) University of Cambridge, UK
6) University of Nottingham, UK

Yes, Taxila is AICTE approved and you are eligible to apply with the scores you have along with the scorecard of either of CAT/MAT/CMAT/GMAT/XAT/ATMA.