I think it's quite common practice in some places, especially in that type of megalomanic and pretentious agencies dealing with pop fluff. Even if the internship doesn't end up with a hired job, they can still say they have work experience in the next agency.

yeah but how do you support yourself for half year with no income especially if you are young with no savings going for internships, we end up again with rich parents kids only

yeah, it's mostly for the young people at the start of their career that can go unpaid for some time and still take money from their parents or drain their fund. such agencies abuse such conditions and exploit it in their favor. since these are a white collar jobs, I guess not a lot of consequences. no one is forcing them to work there.