Yes!

If you're looking only to get into an IIM then it is possible with low academics as IIMs consider only overall performance which includes CAT percentile, work experience, gender diversity, and your academics. Getting calls is an easy process with high CAT score but getting into an IIM is a different story though. Each IIMs have their own admission criteria and the weight given to CAT percentile is also different. Some colleges like IIM Bangalore depend heavily on your academics, and thus lower academics mean you stand a low chance, but other IIMs like IIM-Calcutta go easy on the academics and weigh heavily on the CAT and this becomes your hunting ground. Thus, it becomes important for you to jot down the IIMs you are eligible for and aim for the particular CAT score accordingly. 

Since nothing can be done about the academics right now it becomes rather important for you to score as high as possible in your CAT exam. Assuming you get somewhere around 99 percentile, there is a very high chance of you securing a seat given that you do your PI-WAT very well. With a score like 99 percentile, you will certainly get calls from all the new IIMs, baby IIMs, and sometimes even the old IIMs like IIM Indore and IIM Kozhikode, but getting a call from the holy trinity (IIM ABC) would need a score of more than 99.6 percentile. I personally know students who haven't got a call at 99.5 percentile and I assume you know the cutthroat competition by now.

That being said, once you get a call from the IIMs, another obstacle to cross is the PI-WAT. The PI stories are different and again the weight varies. IIM Indore has around 60% weight and that's the maximum an IIm gives. Again, it depends upon different IIMs. Some IIMs like IIM Bangalore and IIM Indore give very less weight for your CAT percentile ( a mere 25%) and others like IIM Udaipur give 55% to your CAT score while calculating your composite score for the final admission. Thus scoring high only in CAT doesn't guarantee a seat and the real game begins only after that. 

Also, certifications don't really play a vital role while getting calls, but it becomes important during the interview phase.

Good luck. Feel free to contact for further queries.