Test preparation

I don't know much about A.D.O.and B.D.O
But if you want to prepare for Bank PO exam than IBPS PO should be your first step. And for preparation of IBPS PO Recruit you must start your preparation now because there is very high competition in IBPS Exam. Every year thousand of unemployed graduated are applying in it and very few of them selected. you can visit: https://www.eduncle.com/ibps-po-recruitment-exam for more

If getting job is priority and finance is of your interest then definitely you should go for Bank examination. These days banks are having plenty of job opportunities for graduates. But if you have money and time, both in good enough combination then you should try to get higher education and should try for MBA. It will be very beneficial for you.
All the best.!!!

No doubt,if u have caliber opt civil service.But if u r not confident dont waste time,go for hotel management.

This is also a desirable question. Kindly analyse your potential and the biggest thing to keep yourself as techie in the future then opt for M.Tech or wanna be a business leader for tomorrow, go for CAT. All the best

For Medical Entrance Examinations be thorough with the NCERTs of 11th and 12th. Solve as many as possible MCQs so that it will boost your confidence up.

You can do B.Sc hons. in maths,chemistry,computers or go for BA, BCA but since you want to crack CAT so join some institute as early as possible . We have so many institutes today for CAT coaching. Here is a comparison of some good institutes offering coaching for CAT -https://edudrona.com/right-coaching-institute-mba-entrance-cat-xat-mat-cmat-snap-tiss/?mref=tanu
Have a look.
And do as many internships as possible. It will help you build up your Resume and make you confident and help you in GD.