How can I store local files such as JSON and then fetch the data from controller?
Take a look at this Github issue:
https://github.com/facebook/react-native/issues/231
They are trying to require
non-JSON files, in particular JSON. There is no method of doing this right now, so you either have to use AsyncStorage as @CocoOS mentioned, or you could write a small native module to do what you need to do.