I'm also not that familiar with OSC, but I do know you should be able to write software to communicate from an iPhone to the cRIO over WiFi via TCP or UDP. A quick search here on the forums should give you some more information on the network code for the cRIO, and Apple has plenty of resources on the iOS side of things such as
this article.
I'm going to venture a guess and assume you're trying to control a robot from an iOS device? If you're willing to use LabVIEW, I found this article from NI on how to use the NI OSC library for LabVIEW and the TouchOSC iPhone app to control a NI RIO device:
https://decibel.ni.com/content/docs/DOC-20651. Not sure if it's applicable to FRC though.