Steps to install PHP 5.4.3 from rpm and yum

I believe what you are looking for is /var/cache/yum/<repo>/packages. This directory is expunged during package cleanup.

You can search for a file by name with the find command. An example: find / -name 'package.rpm' Wildcards are supported. find -name 'package*.rpm'

I suppose that you want not just “PHP 5.3” (which would be satisfied by the php-5.3.3-* packages included in the base CentOS 6 distribution), but “a PHP 5.3.x version which is more recent than 5.3.3, and the IonCube Loader module built for that PHP version”. In this case you may look at the IUS Community Project, which provides RPM packages for the latest upstream versions of PHP and some other software, built for RHEL (and compatible with CentOS). In particular, this repository provides a recent version of PHP 5.3.x and the IonCube Loader module for that version.

Note that packages from the IUS repository have different package names (e.g., PHP 5.3.x packages are named php53u-*) to avoid conflicts with the base system (as described on The SafeRepo Initiative page), unlike packages from centos.alt.ru which you tried.