Generally, you have to be in a postgraduate degree program (i.e. a masters) but I’m told that rule isn’t always mandatory. It depends on the needs of the organisation.

Of course, I’m not privy to the selection process, but this is what I’ve learned through my experience. I will write an article soon about applying and what I know. Generally, there are no hard and fast rules. As I’ve said, it depends on which departments want interns.