Can anyone tell me the green laning rules in France?

I don't know if it is permitted or not, but you may find this https://fr.wikiloc.com/itineraires/moto-trail/fran... interesting to pick up some useful search phrases.

There is probably club near you,there are clubs for everything in France as you probably know.

My club,in 24, have enduro events every month from March to November.

Normally I understand it is fine on any track that has two wheel ruts unless signposted otherwise, there might be exceptions in National Parks (or equivalent) at certain times of year.
Most countries in Europe are fine with offroad driving/riding. UK seems to be the odd one out and super hateful of that kind of thing, if it helps Bywaymap.com is quite a nice website for England and Wales:


Have a look at the TET (Trans Euro Trail) website for more info.

As mentioned above, some areas are restricted access, not only in National Parks but any area of beauty or interest can have restrictions. A local example for me is about the banks along about10km of the river bank are restricted to horses, pedestrians and pedal cycles. Having said that there are literally thousands of km of rideable / drivable trails in each department over here. Either a club, or the Mairie for the area you're interested in riding in will be able to give you the info you need, and certainly around here the restricted trails are well signposted.

I've got a Dutch mate nearby with a large gite who runs enduro weekends. He'll get up to 8 bikes with a local guide and the guys have 3 full days of riding, out in the morning, stop at a restaurant for lunch then ride all afternoon before food and beer in the evening. Most of his clients are Dutch and they cannot believe how relaxed the locals are with them riding the trails here. Back in NL, he only has to get his trail bike out on his drive at home to clean it and the neighbours are ringing the Police about off road bikes!

It's in Dutch but Deepl should help you!

https://endurofrankrijk.nl