Yamini seems so obvious...
But in suspense shows, "aksar jo dikhta hai wo hota nahi, aur jo hota hai wo dikhta nahi..."😉So if Yamini is shown 5th culprit, no one will be surprised... there wlll not be any suspense element...😉So Ekta may twist the tale & surprise us with someone else... or it may be a new actor...After all, it is not necessary that only Yamini can enter Anky's room... his friend can also enter...