Sorry but I don't see a reason to learn French, unless you enjoy watching French movies.

Wherever you can use French, there's a 95% of chance you can manage by speaking English, too.

You already know English and Russian. You are already very well!

Next, you should bet on another equally known language, such as Mandarin... Or Spanish.

I don't see what use you can possibly give to French. It's not that used.