The calculated distance (air line) between Rong Kwang and Chiang Rai is approximately 113 miles respectively 182 kilometers.
By car or train, the actual journey to Chiang Rai is certainly longer, as only the direct route (as the crow flies) between Rong Kwang and Chiang Rai has been calculated here.
Air line (approximately)
182 kilometers
98 nautical miles