Rovers boss Steve Kean wants Mongongu, 22, as a possible replacement for Chris Samba, who is expected to leave Ewood Park this summer.
Relegated Monaco are ready to cash in and Kean will meet the defender when he returns from Rovers' pre-season tour of Austria. Mongongu, targeted by Arsenal two years ago, is also fancied by West Bromwich Albion.
He said: "Blackburn would be a good opportunity. Let's wait and see what happens."