If you are targeting an MBA then you should not loose your hopes so soon. Usually the levels of AIMCAT or SIMCAT are a little higher than the real CAT exam. So you should at least appear for the CAT exam and depending on that result you can decide whether you want to continue with MBA or go for government exams. But even if you are getting a 70 percentile in CAT you can get a decent college from where you can bag a package of 15 Lpa.

So you should weigh your opportunities based on the final CAT result. All the very best.