How does deferring work?Watch
But if you know your results then you are in a better position to decide whether you are happy taking a gap year and reapplying if they won’t agree to a deferral.
It is unusual for a university to refuse.
Say if I get in with one or two grades below my offer, would my chances of deferring decrease or its the same?
Why not ring them up now and explain that you’re considering it but aren’t sure and ask them how it works. They’ll be able to explain whether they are likely to be helpful or ********s.