"Yes, excuse me!"
In addition to for more than one person usage, we also use -sınız, siniz, sunuz in formal speech to indicate respect.
i think sin is when you talk to a single person, and siniz is used for the plural, many persons
the literally meaning of excuse me in turkish is affedersin/iz pardon can mean sorry or forgive me
Pardon also covers English excuse me. E.g. when getting off a bus or moving past someone, or after a good burp.