The calculated distance (air line) between Neu-Isenburg and Mönchengladbach is approximately 126 miles respectively 203 kilometers.
By car or train, the actual journey to Mönchengladbach is certainly longer, as only the direct route (as the crow flies) between Neu-Isenburg and Mönchengladbach has been calculated here.
Air line (approximately)
203 kilometers
110 nautical miles