Maybe these are the ages?
Rayman 1 - Rayman is 5 years old
Rayman 2 - Rayman is 9 years old
Rayman M - Rayman is 11 years old
Rayman 3 - Rayman is 13 years old
Rayman Raving Rabbids - Rayman is 16 years old
RRR 2 - Rayman is 17 years old
RRR TV Party - Rayman is 18 years old
Origins - 21 years old
Legends - 23 years old
Adventures - 25 years old
Rayman actually struck me as near-adult or adult in Rayman 2, with his English voice [I]in[I] the English and french-voiced incarnations defiantely makes him as an adult. He definately strikes me as older in Rayman 2 than in Rayman 3.
Possibly he's supposed to be timeless, and that's why his appaent age seems to slide around a bit. Though arguably Rayman Origins settled the canon, and I'd say he's probably supposed to be about 18 as of Legends.
In Rayman Legends it says that Rayman was asleep for an entire CENTURY. Let's not forget the fact that Rayman Origins takes place 400 hundred years before Hoodlum's Revenge.Obviously, Rayman is like, 600 years old. And he can live that long, he's not a human or anything.