What do you mean by ja sai in french?

"Ja sai" is not a common French phrase. It is most likely a misspelling or a word from a different language.

Here's what's possible:

* It's a mistake: Perhaps you meant a different French phrase, like "Je sais" (pronounced "zhuh seh") which means "I know."

* It's from another language: "Ja sai" might be a word or phrase from another language, such as Hindi or Thai, which may have a different meaning in French.

To help me understand what you're looking for, could you please provide more context?

For example:

* Where did you hear this phrase?

* What was the context?

* What are you trying to find out about it?

This information will help me give you a more accurate and relevant answer.