You want to protect a RHEL 6.8 (kernel 2.6.32-642.el6.x86_64) system with a DCS agent and it is not listed as supported in the docs that came with the 6.6 MP1 Build 772 agent and it is not installing.
The RHEL 6.8 kernel was certified after the maintenance pack was released.
See attached document for install instructions for the RHEL 6.8 kernel on DCS 6.6 MP1, or use a newer version of the agent.