Has anyone with less than 40 percentile in CAT got into MICA Ahmedabad?

Yes, anyone with less than 40 percentile in CAT has gotten into MICA Ahmedabad. Being a 2015 batch pass-out and back then, MICA accepted a CAT score of 40% and there were certain people in the batch that had a CAT score of a simple 50 percentile. 

But things changed post-2015 as MICA arranged for a separate exam of its own - CAT/XAT/GMAT instead of cut-offs from CAT scores. A good weightage is for MICAT exclusively. Also, back then around 2015, people had gotten into MICA because of their CAT score which was >30 percentile as well. So, you do not have to worry too much.

Focusing on MICAT is a better option. A good or even a bad CAT score in today's time does not really matter. MICAT has two sections to it and make sure you especially excel in their Psychometric test. Having said that, do some introspection and if you happen to realise that there is some kind of potential in you and you are ready to stay persistent in your endeavours to reach MICA. And once you're at it, make sure you do great at MICAT and face GE/PI as well.