In Automation & Control protocols, which is prevalent at the Management level, KNX or BACnet?

Typically, BACnet is widely used for management level integration. KNX is ideally used for residential projects and focused solutions such as lighting, shades control, basic AC controls, guest room management, etc. However, BACnet is used for integrating all these solutions on large platform for large buildings and command center operations. 

Sure BACnet has higher flexablity and more related to the BMS.

KNX are mostly used in the Hotels for the GRMS and Lighting control.

BACnet over IP is prevalent in all building automation and control protocols.