Hey Mithun.

The BHU Faculty of Science (main campus) has 460 seats for B.Sc (hons) maths and Mahila Mahavidyalaya, BHU has 77 female seats. 

BHU also have provision “Paid Seats”, these seats are supernumerary and the maximum percent of such seat is 15% of the total number of seats. The fee for the paid seats is higher than the regular seats, this is simply because being the Central University, BHU charges only a fraction of the total cost incurred for its regular seats. However, for the paid seat the student has to incur all the expenses.

Students who are willing to take the admission in the course but could not on the basis of their rank (or could not get the combination they wanted) on payment of the full fees of the course.  Therefore, many candidates get ready to pay extra are called paid seats in BHU.

Hope this serves your query. Please feel free to respond and ask further questions. 

All the best.