I have followed this and it is working fine
NSError *error = nil;
NSString *filePath = [[NSBundle mainBundle] pathForResource:@"messages"
ofType:@"json"];
NSData *dataFromFile = [NSData dataWithContentsOfFile:filePath];
NSDictionary *data = [NSJSONSerialization JSONObjectWithData:dataFromFile
options:kNilOptions
error:&error];
if (error != nil) {
NSLog(@"Error: was not able to load messages.");
return nil;
}