Well if they offered ABB and you get BBB then you haven't met the conditions of the offer so they are under no obligation to give you a place.
Yeah but he's asking will he still have an offer and I'm just saying that Birmingham isn't obligated to give him a place if he doesn't meet those offer conditions. Birmingham may accept him with lower grades, but then they're reducing their offer to meet his qualifications.
3B refers to getting 3 B's. It means that the university may accept people with lower qualifications despite them not reaching the offer criteria simply to fill up the numbers. So if there are not enough people who are coming to the course they will begin to begin accepting students who have less than ABB grades.