Does Octopus Deploy Tentacle for Linux support RHEL 6?

The short answer is no.

Our documentation states that Tentacle for Linux is distributed as self-contained .NET core application. Self-contained applications do not rely on shared-components being present on the target system, all of the necessary components for the application to run are included within the application itself.

Red Hat Enterprise Linux 6 (RHEL 6) required the Runtime Identifier (RID) rhel-x64 RID whereas linux-x64 is compatible with most distributions like CentOS, Debian, Fedora, Ubuntu and RHEL 7+. Rather than support two versions of Tentacle for Linux, the decision was made to use the linux-x64 RID.

Here is a list of Linux distributions that are supported.