Hi Sudip Ghosh !

Well your OBC B rank in your WBJEE examination is 90 . The cut off of Jadavpur University , Kolkata this year depends on the previous year trends . For OBC B category and for Mechanical Engineering Previous Cut Off was :-

2017 - 1300 Max. Closing Rank

2016 - 1251 Max. Closing Rank

Source :- https://www.careers360.com/university/jadavpur-university-kolkata/cut-off?cid=892&college_id=49440&exam_id=1095&seat_type=1114&category=83665