Hi there, I work in University admissions.
Your best bet is to discuss this with either the academic staff who’ll do the teaching, or the admin staff (like me) who’ll do the processing of the application. Both sets will be honest with you, and if it’s a definite no they’ll tell you about it.
However if you just email them and say you don’t make the grades it won’t give them a lot to go on, to make a case for you.
I recommend you write some (brief) paragraphs about why you want to study on the course, what skills/experience you have that means you’ll be an asset to their cohort, and show that you’ve read up about the course content! So many people want to study just based on the course title but don’t look into the specific module information! So yeah, doesn’t need to be a long essay, like half a page of A4 or less maybe? Going to a postgrad open day could also help.
Some universities are stricter than others when it comes to their advertised entrance requirements. But the vast majority are willing to go lower. Do you think it’s possible you can get 60% overall? That still puts you in a positive position. If not, it’s still worth trying. Even if there’s only 8 places, it could be that the other people applying are in similar situations to you.