How do you say hello what are doing in french?

There are a few ways to say "hello, what are you doing" in French, depending on the level of formality and the context:

Formal:

* Bonjour, que faites-vous? (This is the most polite and formal way to ask.)

Informal:

* Salut, quoi de neuf? (This is a casual and friendly way to ask.)

* Coucou, tu fais quoi? (This is a very informal and friendly way to ask, often used among friends.)

You could also use a more specific greeting:

* Bonjour, comment allez-vous? (Good morning, how are you?)

* Bonsoir, comment allez-vous? (Good evening, how are you?)

* Salut, ça va? (Hi, how are you?)

Remember to adjust your choice of greeting based on the situation and your relationship with the person you are talking to.