- OpenVPN does not have a "redirect" option, nor does it have a "redirect-gateway-ipv6" option, so neither of your configurations would work on any OpenVPN setup. I assume those were just typos and you meant "redirect-gateway ipv6" and "redirect-gateway ipv6 def1".
- IPv6 DNS and other leaks can be prevented by putting a check in Tunnelblick's "Disable IPv6 (tun only)" checkbox for the configuration.
- Tunnelblick itself does not support IPv6 (except via #2 above); the only other support for IPv6 it has is whatever is included in the version of OpenVPN that is being used.
In the future, please follow the instructions at Read Before You Post to get the info needed to diagnose problems and then post that info with a description of the problem.