Excuse Me
Hello
interjection
It's kind of like you're saying say say, and it’s used in classical Japanese to get someone’s attention, so this is excuse me or hello.
You would generally encounter 申し申し in dialogues set in older times, unlike its modern, shortened version もしもし, which is used for telephone greetings (and almost always written in kana).
This word uses the reading you learned with the kanji. You should know it already.
申し申し、レストラン「山びこ」です。
Hello, this is "Mountain Echo" restaurant.
申し申し、田中先生のご主人ですか？
Hello, are you Tanaka-sensei's husband?
「申し申し。先日メールをいただいた山下です。」
"Hello. This is Yamashita. You sent me an email the other day."