Jet Airways never had any 787 dreamliner. According to 9W website, it has A330-200, A330-300 and B777-300ER in wide body category. Rest are B737s in narrow body and ATR72s in tubo-prop categories. If it is planning to fly wide-bodies in CCU-IXB sector, it has to be A330 or B777, but I assume, the CCU hub of 9W don't have any wide bodies. If it is B787, the carrier has to be AI.
Jet Airways fleet
click here