Dear, 

It has been made mandatory for all students which fall in caste to have a non-creamy layer certificate, caste validity certificate and an income certificate. If you fail to submit these during your admission, you won't get admission upon you category rank but you will be treated as a general category student. So, then the colleges you would get would differ. You may get a good college if you submit these documents and you will also be given fee concession because of your category. These are some benefits of being a category student. If you fail to do so, you would get a college slightly less in ranking. I suggest you to make sure you have all these documents.

Hope this helps!All the best.