i have no idea of the percentile that I would be getting.. and the application fees of the colg are very high.what should I do

Hy,
You are in dilemmna right now of what to do or what not to do. I completely understand your situation.

CAT 2017 cutoff will depend upon various factors. Some of the factors determining CAT cutoff can be mentioned as follows:

Difficulty level of exam

Number of test takers

Number of candidates qualifying for the next rounds

Number of seats

Institute repute or ranking

So your percentile will depend upon your accuracy of right answers. I hope you will get a good percentage.

For application fees one thing you can do that just wait for cat results to be out and then there are chances that some institute will reopen its application process and then you can apply for the same.
I think this is the safest option you have.
I wish you all the best.
Cheers !!

There are two things, first you need to have an idea how much percentile you will be scoring atleast a range like 80-85%, Above 90% and you can fill colleges accordingly.

Second thing is that there are some colleges who open or reopen their forms after the CAT results are declared. This includes all the IITs like SJMSOM IIT Bombay, VGSoM Kharagpur, DMS IIT Delhi, NITIE etc and other private institutes also reopen their forms. Though there is a risk involved in this option but this can be considered as a an option.

All the best!