In order to conserve the limited bandwidth available, ISO images are not downloadable from mirror.centos.org

http://mirror.cs.vt.edu/pub/CentOS/6.10/isos/x86_64/
http://repos-va.psychz.net/centos/6.10/isos/x86_64/
http://mirror.vcu.edu/pub/gnu_linux/centos/6.10/isos/x86_64/
http://mirrors.advancedhosters.com/centos/6.10/isos/x86_64/
http://repo1.ash.innoscale.net/centos/6.10/isos/x86_64/
http://us.mirror.nsec.pt/centos/6.10/isos/x86_64/
http://mirror.cogentco.com/pub/linux/centos/6.10/isos/x86_64/
http://mirror.ash.fastserv.com/centos/6.10/isos/x86_64/
http://mirror.vtti.vt.edu/centos/6.10/isos/x86_64/
http://mirror.centos.iad1.serverforge.org/6.10/isos/x86_64/
http://centos4.zswap.net/6.10/isos/x86_64/

http://mirror.cisp.com/CentOS/6.10/isos/x86_64/
http://mirror.linux.duke.edu/pub/centos/6.10/isos/x86_64/
http://mirror.sfo12.us.leaseweb.net/centos/6.10/isos/x86_64/
http://centos.mirror.lstn.net/6.10/isos/x86_64/
http://mirror.dal10.us.leaseweb.net/centos/6.10/isos/x86_64/
http://mirrors.oit.uci.edu/centos/6.10/isos/x86_64/
http://mirror.es.its.nyu.edu/centos/6.10/isos/x86_64/
http://mirrors.seas.harvard.edu/centos/6.10/isos/x86_64/
http://mirrors.lug.mtu.edu/centos/6.10/isos/x86_64/
http://linux-mirrors.fnal.gov/linux/centos/6.10/isos/x86_64/
http://mirrors.codec-cluster.org/centos/6.10/isos/x86_64/
http://linux.mirrors.es.net/centos/6.10/isos/x86_64/
http://mirror.sesp.northwestern.edu/centos/6.10/isos/x86_64/
http://repo1.dal.innoscale.net/centos/6.10/isos/x86_64/
http://yum.tamu.edu/centos/6.10/isos/x86_64/
http://mirror.den01.meanservers.net/centos/6.10/isos/x86_64/
http://mirror.ancl.hawaii.edu/linux/centos/6.10/isos/x86_64/
http://linux.cc.lehigh.edu/centos/6.10/isos/x86_64/
http://mirror.arizona.edu/centos/6.10/isos/x86_64/
+ others, see the full list of mirrors: https://www.centos.org/download/mirrors/

Mirrors verified Tue Apr 7 22:25:17 2020 UTC

You can also download the ISO images using bittorrent, a peer-to-peer file sharing protocol. The .torrent files can be found from CentOS mirrors. Various bittorrent clients are available, including (in no particular order of preference): utorrent, vuze (Azureus), BitTorrent, Deluge, ctorrent, ktorrent, rtorrent and transmission. Packaged copies of various torrent clients for CentOS can be found in the repositories listed in the following wiki article: https://wiki.centos.org/AdditionalResources/Repositories