Should you tell a reporter something off the record? Well, firstly, what is off the record? Off the record is when you tell someone something that you don't want repeated to anyone or run in the media. Now, it's generally information that's personal or extremely sensitive, controversial. Perhaps, if you tell reporters something off the record, what you're effectively doing is saying to them, I'm happy to share this information with you, but you can't report it. There.
My advice, don't do it. What it tends to do is frustrate the reporter. Some reporters will run the story anyway. So again, my advice is simple. If you don't want something broadcast, keep your mouth shut.