Hey! 

I would request you to give another shot next year. As this marks won't fetch you a good MBA college, even if its private. Prepare well and ace it next year. There are numerous cases when students even end up coming to IIMs in the next year. So, don't quit and start preparing for it. Best wishes! 

No, don't prepare for the examination

CAT is for the candidates who work their a** off for atleast 6 months (in general) of preparation and countless number of mocks. And even after that many of them end up in scoring in between 90–95℅ile which is not acceptable for top IIMs.If you are willing to give CAT 19 then leave everything behind and start the preparation seriously.

Else it's just a waste of time and money to rely on luck with little or no preparation.