Sir if i got 78 percentile in CAT i am OBC student so thr colleges / institution i can get ???

Colleges nowadays dont only consider Cat percentile but also past academics extra curriculars and work experience. So only on the basis of Cat it is difficult to predict the college you can get in. Moreover reservation benefits are only available in Govt. related/sanctioned/ran colleges.
Below is the link for colleges in various range of percentiles have a look at it.

http://www.google.co.in/url?sa=i&source=web&cd=&ved=2ahUKEwjfiY3J0fTeAhXLrY8KHanCAhEQzPwBegQIARAC&url=https%3A%2F%2Fbschool.careers360.com%2Farticles%2Fcleared-cat-cut-offs-for-various-b-schools&psig=AOvVaw3-Tm9cHGY3iQVvm_wf2xFI&ust=1543410305125120

Apply for IIMs as well you might qualify for some of them.
Hope this answers your query.
All the best.
SMIT-IIM-AMRITSAR-PGP/04