Oops, I just saw the ringneck part.
Ok, how about 25-30 years, then. lol
http://www.indianringneck.com/ Looks like they may have a discussion forum, too.
http://birds.about.com/od/breedsofbirds/p/IndianRingnecks.htm
(I hope I got the correct species this time!)
Looks like 15-20 years with proper care.
http://www.diamonddove.info/bird11%20Ringneck.htm
http://www.diamonddove.info/bird11%20Ringneck.htm#Longevity
I love mine. Olivia is almost 10 years old and just raised another pair of gorgeous sweet babies.
Enjoy yours, I think they're sweet.