After installing epel and remi repository and enable remi-php56, the php packages still not available.
The issue is i just uninstall Cpanel from my Centos 6 server. Cpanel disable php packages from showing up in you.

#vim /etc/yum.conf


[main]
exclude=php* ..

Just remove php packages from the exclude section of the /etc/yum.conf.
It waste 3 hours of my time to figure this out.. :(