I was able to pull up a seatmap for a dummy booking (intra-Europe). The exit row looked like it was blocked and 4 of the seats in row 4 (first in eco) were occupied plus one further back.
Called TK and agent told me call back 7 days before the flight. I am about 30 days out now.
Are TK *Gs able to select seats or how do you explain the handful of seats selected? I checked another flight the same day and also found a handful non-exit seats taken.