What is the practical non-LOS(line of sight) range of XBee-PRO 900HP?

HI, I am working on a project for which i need any RF front end having range atleast 6 miles non LOS (line of sight) in urban and mountain areas . currently I am planning to use XBee-PRO 900HP which has 28 mile LOS range. Can you help me with practical non LOS (line of sight) range of the XBee-PRO 900HP ?

There is no way to estimate the non line of site coverage. You must measure the coverage through the obstacles that are in place, trees, buildings etc.