hi,

see the cutoff which mentioned in ews and obc ncl of jee main score is only the eligibility cutoff of each category to appear in jee advance. however there is no special benefits of any thing, now admission to iits would depends on the cutoff score in jee advance exam, questions difficulty level, number of applicants would appear in the exam. however you may enroll for careers360 jee main college predictor tool to know about probable college name based on your jee main score,

https://engineering.careers360.com/jee-main-college-predictor?icn=QnA&ici=qna_answer