The Legislatives are on the 11th and 18th June, two rounds as per the presidentials.
The current number of seats out of 577 are 2 for FN and 0 for En Marche so could be anyone's guess.
Personally don't think FN will get many, no idea how many EM will get but believe the will be UMP, Mélenchon and PS will get a lot between them
As for polls I look in different places but one site seems to summarise the lot as below
http://www.linternaute.com/actualit...e-2eme-tour/#resultat-election-presidentielle