CBSE 10th

If you want to join the top B-school, then you must score in the entrance exams, because it is not that much easy to get through these top B-schools. All the reputed B-schools such as IIMs, and other renowned management institutes in India admit students not only depending on their graduation marks, but also with a valid rank in the entrance tests like CAT XAT MAT etc. Competition is so hard out there that you have no scope to escape from this. So, if you are dreaming of those top B-schools, then start the preparation from now.

For IIM admission you need 80% in graduation.

It depends upon your profile as well as how you performed in GDPI. On the Basis of evaluation and the courses that you have applied for, you will be selected accordingly. Looking at your profile, you have a good chance.

Your profile is good. You have high chances of getting a call. Go ahead and apply.

First of all, will you be specific and what do you mean by saying "campassing in the plea”?
Other than that, search for institutes where the criteria is 50% marks above, since your +2 marks is 57%.
Also, there are organizations where candidates with 50% marks and above get a chance to be recruited.

No, firstly you have to complete your class 12th for any graduation degree. It is a must to complete class 12th. After that, you can surely apply for what you want.

Yes, you stand a clear chance.
All the best.

Yes, it is definitely okay to drop a year for CAT preparations but if you work hard for it, not just for fun because CAT is not an exam which can be qualified easily. This exam is conducted to check the capability and Eligibility of a student who want to study in IIM and B business colleges. So, if you can consume work time, you can do it but if you cannot qualify that a drop will not be good for you.
Good luck.
Thank you.

Yes, you can take IELTS after 10th.