I am far from being proficient in French but I will say that my experience with Alliance Française has been largely positive. Needless to say it would also depend on the teachers available in your locality but from what I gather, the institution has very high standards and you’re sure to get teachers with native level proficiency. The Fees aren’t that high either. Especially when you compare it with other online offerings.
Also, you might want to check out ‘Inner French’. The September intake has already begun. But the suggested Niveau is somewhere between A2 and B1 for this course. Have a look at their podcasts and videos as a sort of reference guide. If you’re able to understand close to 50% or more, you’re good to go.
My own Niveau is somewhere around the A2 mark so I’m afraid I’d be quite unsuited for the task of teaching. However, I am more than happy to practice alongside anyone learning the language.