How to ask an university for application selection result before accepting an offer from another university? I have an offer from one university and still awaiting results from others.

How to approach other universities and ask them about my application status so that I receive my selection / rejection before the deadline of accepting the offer? Is it rude to inform the universities that I have an offer from another university and will be accepting if the results are not announced before the deadline?

All the universities are in the same region.
A related, but not truly duplicate, answer

Just ask. Tell them you have been accept at X, but Y is your first choice. The admissions committee does not need much explanation since it happens all the time. Asking to speed up the process will not hurt your chances. They may not be able to speed anything up, but if they do/don't, they will not hold it against you.