My issue is:
Failed (/usr/lib/libstdc++.so.6: version `GLIBCXX_3.4.20' not found (required by plugins)
I have installed g++ (GCC) 4.9.1 20140922 (Red Hat 4.9.1-10) and centos version 6.10 (64 bit)
This means you downloaded an RPM or pre-compiled binary that is using a newer version of the main C/C++ libraries on your machine. These cannot be changed. You need to (a) find an RPM version specifically built for your version of CentOS (or earlier), (b) recompile the source code or RPMs on your machine, or (c) use a container (like Docker/Moby) and run it inside an image that has the newer libraries.