Hi, I did attend a PhD interview (consortium project cum PhD) and supposed to get answer within a week. I waited more than a week and I did not get it any response from their end. After a week, I sent a gentle reminder asking about the interview result but still they are calm. Now it's almost two more than two weeks over. I am not sure how to get answer from them "yes" or "no"?

It's too early to expect the whole process to be concluded within 2 weeks. You are probably not the only one interviewed, some interviews are scheduled over a period of two weeks, depending on availability of interviewing panel and/or the candidates being interviewed. A decison can only be made once all shortlisted candidates have been interviewed. Some PhD interviews that I did took up to 3 months to get a response. For my current PhD position, I was interviewed around 20th March and only got a response on 22nd May (I always commemorate this day, lol). So just give them time, they'll make a decision.