Further down on that
same page you will see that even the optional (extra cost) Extended Update Support for those point releases has already ended.
- 5.6 (ends July 31, 2013)
- 6.5 (ends November 30, 2015)
If you keep RHEL 5 and RHEL 6 fully updated, regular support continues until Mar 31, 2017 and November 30, 2020, respectively.