I have MySQL 5.6 working with RHEL 6.7. You should be able to get MySQL 5.5 working.
That message about "Some required packages were not found" concerns me. Quick guess is that you're missing some compatibility packages.
I have Ansible playbooks for doing a base IMC + local MySQL install. Looking through those, you might want to check you've got these packages installed:
- glibc.i686
- libaio.i686
- libgcc.i686
- libstdc++.i686
- ftp
- telnet
- ksh
(Note that several of them include ".i686" - it's not enough to just install libaio, you must install libaio.i686, so that it installs the 32-bit versions, not just the default 64-bit versions.)
Are you using a local MySQL install, or remote? If you're using local, you need to make sure MySQL is using a password for connecting from localhost. IMC won't work otherwise. It's a confusing thing to debug because when you run basic mysql queries yourself everything seems to work as expected.