Hi,
Seems that a few source RPMs are missing from the link: http://mirror.centos.org/centos-6/6.0/os/SRPMS/Packages/
(bash, nss-util, I could attempt to make a list if needed)
These are available here: ftp://ftp.redhat.com/pub/redhat/linux/enterprise/6Server/en/os/SRPMS
Will missing the mirror be updated soon?, can I help?
Thank you, Adrian