The calculated distance (air line) between Tarn Tāran and Derā Nānak is approximately 41 miles respectively 66 kilometers.
By car or train, the actual journey to Derā Nānak is certainly longer, as only the direct route (as the crow flies) between Tarn Tāran and Derā Nānak has been calculated here.
Air line (approximately)
66 kilometers
35 nautical miles