As there is no official record, it's difficult to know the lowest percentile accepted for admission at IIM Ahmedabad. But I know students who got admission with a percentile as low as 63 from engineering backgrounds.
But note that for 2022 IIM Ahmedabad cutoff is expected to be around the 99 percentile.
As much as I know, many students with low percentile too get admission in IIM Ahmedabad with a percentile less than the admission criteria. I have a few friends from IIM Ahmedabad and they were able to shed some light on this. Here is what they had to say.
According to my friends, not many students in the batch possess less than 90%ile. And for an MBA aspirant, I want to advise you that stop thinking of high and low percentile. Whether you belong to a category with reservation or not. Prepare well and give your best in the exam.