We (2) are arriving by train in Paris on a Monday and leaving the next Monday. Besides travel around the city, we're including trips to Auvers-sur-Oise (zone 5) and Fontainbleu (zone 6). It seems that a Navigo Semaine is a better idea than carnets or mobilis. Also, the SNCF timetable shows the RER-C to Saint-Ouen-l'Aumône and then a transfer to what is described as train TRIA to Auvers. Since the last leg is not on the RER, does the Navigo Semaine apply to that portion of the trip? Please advise.
Single tickets from Paris to Auvers-sur-Oise cost 5.05 EUR each way. Single tickets from Paris to Fontainebleau-Avon cost 7.90 EUR each way. So yes, a zone 1-6 passe Navigo Decouverte (37.60 EUR) would serve you well since you'll only be paying the equivalent of 11.70 EUR for all your rides in central Paris for one week. And the bus ride from Fontainebleau-Avon to the chateau is also covered by the pass.
Your Navigo pass will be good on SNCF above ground trains as well as on the RER in all zones covered.
Thanks - you've certainly helped in the decision. Now to take some pictures to apply to the Navigo passes.