If you have a 99.5+ percentile in CAT, you have a good chance to get selected in IIM A, B, C, or XLRI. One of my friends was in a similar situation and these points helped him understand the proper requirements to get an interview call from these institutes.
Getting 99.5 percentile in CAT/ XAT is not an easy task, and requires a lot of hard work, dedication towards studies, and a never-give-up attitude. Such a score has good chances in all the top Business Schools in India.