Formal:
* Bonjour, maman. (This is the most common and polite way to greet your mother.)
Informal:
* Salut, maman. (This is a more casual greeting, often used with family and close friends.)
* Coucou, maman. (This is a very informal and affectionate greeting, similar to "Hi, mom.")
* Maman, ça va ? (This translates to "Mom, how are you?", which is a common way to start a conversation with your mother.)
The best way to say "hello mom" in French depends on your relationship with your mother and the context of the conversation.