Greetings!

Hope you're doing great.

According to CAT reservation policy, 27% of the seats are reserved for NC-OBC, 15% for SC and 7.5% for ST candidates, 3% seats are reserved for Persons with Disabilities (PWD) candidates.

Being from the reserved category will surely be an added advantage. However, there are several other parameters that one has to look before landing to an expected CAT score. To get a call from IIMs no doubt, one has to score exceptionally high to get a call from top IIM(A+B+C). If you look at the cutoff of the OBC-NCL one can expect a call between 95-97 percentile to be on a safe side, given that you have a decent previous track record. 

I'll suggest scoring as high as possible to make sure you can get the most of it. Aiming 100 percentile should be your target.

For more details on college wise cutoff in CAT exam: https://bschool.careers360.com/articles/iim-call-cutoff-vs-shortlist-cutoff-know-huge-difference

Hope you will be mutually benefited. Do reach out in the comment section below if you need any help. 

Have a wonderful day ahead. :)