I have 78% in my 10th and 57.2%(in my 12th(ISC) and 69% in my graduation b.sc.Is there a possibility to make into IIMs or decent b-schools?

There is equal chance at all the colleges, Mostly you require minimum 98 percentile to get call from IIMs.
If you score around 90 percentile then chances for IIMs are fairly low.
On the contrary, Other colleges lkke PSG,Great Lakes Chennai, LiBA open up chances for you.
You have got decent academics so ggat should help you as well.
Kindly check top college under CAT:-
https://bschool.careers360.com/colleges/ranking/2016/top-mba-colleges-in-India-accepting-cat-score

Top IIMs may be difficult but not impossible (see IIMA selection criteria based on discipline https://insideiim.com/can-get-interview-call-iim-ahmedabad-cat-2016-pgp-2017-19/?src=quora), you can focus on the IIMs outside of ABC from preparation point of view.


In fact IIM-C provides sufficient room for people with better CAT scores.


Beside other colleges viz. FMS, XLRI, DoMs of IITs, etc. too undoubtedly  have world-class faculties and at par placement records, which you might consider for your preparation.


Please do check on the selection criteria set by IIMs for Tha academic year 2018-20


http://www.time4education.com/CAT-MBA/Admission-Criteria/IIM-Admission-Criteria

Sayyed - IIM Raipur



Yes, there is.

If your CAT score is high enough, you will get IIM calls. And if you perform well in personal interview, group discussions or written ability test you can convert your IIM call. If you have work experience it will further help you.

Not all bschool consider your past academics. Even in few IIM's your past academics are not strictly taken into account.



Yes you can make to various good bschools and it depends upon 2 things mainly:

First, do not limit to only CAT, give various entrances for management and keep wide scope for your chances.

Second, Aim at scoring above 95 percentile to get admission in good bschools, irrespective of academic records.



Applications are on for CAT, XAT and even MAT.

The selection process in all bschool varies.

Like in some colleges there are selection rounds like GD, PI. WAT and Extempore.



IIM selection criteria is explained well in the link below for top IIM's



Selection Criteria for IIM's





Also work on your preparation. Start with a systematic study plan and be sincere with the plan you make.

Attempt previous year papers so that you can judge which sections you are good in and what other sections you have work hard on.

Take professional help incase you feel its difficult for you to prepare by self.



All the best!