Hello Shubahm,

It depends upon your examination subject. If you are looking for arts group then 250 marks are enough whereas, for admission in Science group, 70% marks in entrance exam can be considered as a good score. For hostel, You have to be top ranked, otherwise you will have to wait for hostel after admission.

http://bhuonline.in/pdfs18/UET-Bulletin-2018.pdf

Good Luck.