The isotopism problem of a class of 6-dimensional rank 2 semifields and its solution

In [5] three classes of rank two presemifields of order q2nq2n, with q and n odd, were exhibited, leaving as an open problem the isotopy issue. In [18], the authors faced with this problem answering the question whether these presemifields are new for n>3n>3. In this paper we complete the study solving the case n=3n=3.