Hello Akansha,
According to the cutoffs released by the allahabad university, it is unlikely you would be able to get admission in the main campus with 140 marks in the entrance test OBC category. The cutoff is 165 marks and above. However, you can try other affiliated colleges of AU.
More - https://university.careers360.com/articles/allahabad-university-cut-off
Hope this helps.
Regular exam updates, QnA, Predictors, College Applications & E-books now on your Mobile