Class 6400 locomotives when introduced, were used prominently on high-end passenger trains like Padma Express, Silk City Express and Maitree Express. Now they are mostly used on freight trains as Class 6500 and Class 6600 locomotives are used to haul most high-end passenger trains. Intercity trains like Kapotaksha Express, Titumir Express, Sagordari Express are also hauled by these locomotives.