You can take a train from Nagpur to Narsinghpur via Itarsi Junction (ET) and Kareli (KY) in around 8 h 40 min.
How to get from Nagpur to Narsinghpur
From Nagpur bus to Jabalpur then taxi to Narsinghpur. 8 h 5 min ₹2,333. From Nagpur (NGP) train to Itarsi Junction (ET), train to Kareli (KY), then taxi to Narsinghpur. 8 h 40 min ₹2,035. From Nagpur taxi to Narsinghpur. 3 h 38 min ₹4,648. From Nagpur drive to Narsinghpur. 3 h 38 min ₹2,007.