Hi, 2 weeks ago I got a call from NTNU that i have been shortlisted but still didn't get any email or call about the interview? how long usually it takes to inform you and is it ok to contact them

I think it's totally okay to contact them again. Ask them when is the interview going to be held. Be polite in your email.

Hi , thanks for your reply. i will wait 2 more days and then contact them

Always remember the HR people you correspond with are not the academics making the decision.

I've seen people go out of their way to treat HR departments exceptionally cautiously and politely like they're the hiring academic. There's no harm in being polite, but you're not liaising with the person deciding on the hire, so don't hesitate to ask them questions or chase them up on things.

I have seen it happening when hiring, that HR can easily screw up and fail to contact people. In one case an applicant was a colleague, when I told them to phone it turned out the interview was within 24 hours, they were invited, but never received a communication.

It may mean if uncontacted your application was unsuccessful, but you burn no bridges chasing an HR department for a concrete answer.

Thanks, contact them and they said it will take time and either way I will get the response. hope for the best

This is the first application and I was away from academia for a while, kinda confused about all the process

I agree....By "being polite", I meant being gentle, not outrageous. I myself contacted the HR about the outcome of an interview at a later date and am doing the postdoc now!