It is simple. The Konkan Kanya which arrives in the morning at CSTM, returns to MAO as Mandovi. Similarly the Mandovi which arrives at CSTM in the evening returns as Konkan Kanya. Regarding the coach composition, Broad Gauge is correct, as Mandovi is a day train, to provide a less expensive travel (both ways) to passengers some of the sleeper compartments are marked as 2S.