Known from various parts of the middle and upper Mekong river basins with record existing from the Nam Tha, Nam Ou, Nam Khan, Nam Lik, Nam Ngum and Nam Mang tributary systems in Laos, the Nam Noeua (a tributary of Nam Ou) in Vietnam, and the Mae Nam Kok in Thailand.

Occurrences in the Chao Phraya drainage in central Thailand most likely refer to the congener R. chiengmaiensis.

This species is distributed in the middle Mekong River basin in north and northeastern Thailand, Myanmar and Xishuangbanna Dai Autonomous Prefecture, Yunnan province, southern China, and is also known from the Nam Beng, Nam Tha and Nam Yuoan drainages in Laos.

Type locality is ‘Laun We (Loi Mw…