you have 11 hours between flights, more than enough to take a RER train into the city and sight see before heading to ORY

I'd suggest looking at some postings here for things to see, pick a few, and plan on leaving for ORY (again on RER) around 2-1/2 hours prior to departure of next flight

EDIT: you won't see that much of interest coming and going by RER but there's time when you're in the city