You want to know if you can use a 6.7.x agent with an older Data Center Security (DCS) Management server.
We do not support combining newer agents with older Managers. This can lead to unexpected behavior in the environment.
You can find specific reference to this in the Planning and Deployment Guide :
*The DCS 6.7 agents are only compatible with DCS 6.7.x managers. Do not use the DCS 6.7 agents with older manager versions.*
As well as the Platform Support Matrix