" First he should stop being stressful and asking question of others what can be on interview. If he has knowledge and luck he will pass. Sometimes is more about luck than knowledge but generally If he will get too stressful, even luck won’t help him.
About question they can ask whatever they want from just:
- How are you?
- Where you were studding?
- What you were studding?
- Why do you decide to have interview with us?
- What programming languages you know and how well?
- What engines you know?
If he sent them CV there will be probably few question about stuff you put there. If he worked previously somewhere I would expect question like:
- What you done in previous job?
- Why you decide to change job?
- What projects you done in university?
- Why you think this position is for you?
So returning to first line if he has knowledge he will answer questions better or worse but he will do this. From my experience, there are always different questions on each interview (but maybe this is just for me). He should chill-out and just see this as learning experience. If he will fail, world don’t end and he should just learn from it and try again. If they will see potential in him there is still big chance they will at least give him programming task.