See, your academic records are not that bad. You might even get into IIMs except A,B,K if you score exceptionally well in your CAT. You must target for 98-99 pecentile to get a call from other IIMs.

There is again no surety of selection or getting a call from these colleges because CAT marks are not the only parameter involved in the selection procedure. After CAT exam every college in which you have applied prepares a merit list to call students for next round of interview based on your aggregate score which comprises of many parameters such as CAT marks, 10th, 12th and graduation percentage, work experience, engineer or non-engineer whose weightage varies for all different colleges. Academic records generally have a weightage of 10-25%.

Your academic records are not something which you can undo now. So stop thinking much about them and start your preparation for CAT'19 and give it a shot. 6 months are enough to prepare for it. All the best!!