Here are the steps that I followed in order to fix the timezone sync issue on Cent OS 6 linux:

Take the backup of the timezone file:

mv /etc/localtime /etc/localtime.bak

Next, create the symbolic link to the respective timezone file:

Next, create the symbolic link:

ln -s /usr/share/zoneinfo/America/Indianapolis /etc/localtime

Stop Service NTPD:

# /etc/init.d/ntpd stop

Do manual sync:

sudo ntpdate

Start Service NTPD:

sudo /etc/init.d/ntpd start

Enable IPTABLES firewall to communicate with NTPD:

iptables -I INPUT -p udp --dport 123 -j ACCEPT
iptables -I OUTPUT -p udp --sport 123 -j ACCEPT