i applied for DU LLB under unreserved category by mistake but i actually belong to EWS category, the exam has happened i have all the documents related to this, so will they give me admission under EWS?
Unfortunately, I don't think anything can be done about it at this point. The problem is that had you applied through EWS category in the beginning you would have been given an EWS category rank which would have been used for your college admissions and seat allocation right till the counselling process where they'd have asked you for your EWS certificate.
As it stands, the situation is that you will not have your name in the EWS category list of ranked students and so the universities providing admission will not look much into it as they have their own guidelines to follow when it comes to seat filling.
Since there is not much of a difference in EWS ranking and General ranking of candidates in most exams, I am assuming and really hoping that it is the same in your case so you should be able to get the same colleges (+1 or -1) that you'd have got with an EWS rank.
Best of luck for your admissions!