Superintendent of Police Prasun Bandyopadhyay said the victims were crossing the tracks at around 7 AM when they were mowed down by the speeding train.
Five of the deceased had come from Ajamnagar in Katihar district of Bihar to visit a relative.
The sixth victim, who had been accompanying the other five, belonged to Lotora village under Harischandrapur police station, police said.
The incident occurred near Baroduari under the same police station, around 90 km from the district headquarter, the SP said.