For this train reservation has not started yet. Today only Central Railway has started reservation for 0167 towards Kochuveli. For train #0168 Southern Railway has to start the reservation. They have not yet staarted it that is why it is appearing as TRAIN CANCELLED it is quite common for SPECIAL TRAINS. So keep on checking suddenly they will start booking sometimes with a couple of days or else it will take a week or more. So keep on checking.
GOOD LUCK.