I needed to install php-mcrypt on my VPS because of an application and well, below is how i did it.

Download package – Install using yum – Restart Apache

[root@s16960602 ~]# rpm -ivh http://dl.fedoraproject.org/pub/epel/6/x86_64/epel-release-6-8.noarch.rpm
Retrieving http://dl.fedoraproject.org/pub/epel/6/x86_64/epel-release-6-8.noarch.rpm
warning: /var/tmp/rpm-tmp.Qzis3Y: Header V3 RSA/SHA256 Signature, key ID 0608b895: NOKEY
Preparing…                ########################################### [100%]
1:epel-release           ########################################### [100%]
[root@s16960602 ~]#
[root@s16960602 ~]#
[root@s16960602 ~]# yum install php-mcrypt
Loaded plugins: fastestmirror, priorities
Loading mirror speeds from cached hostfile
epel/metalink                                                                                         |  11 kB     00:00
* epel: mirrors.servercentral.net
base                                                                                                  | 3.7 kB     00:00
epel                                                                                                  | 4.2 kB     00:00
epel/primary_db                                                                                       | 5.3 MB     00:01
extras                                                                                                | 3.5 kB     00:00
updates                                                                                               | 3.4 kB     00:00
Setting up Install Process
Resolving Dependencies
There are unfinished transactions remaining. You might consider running yum-complete-transaction first to finish them.
–> Running transaction check
—> Package php-mcrypt.x86_64 0:5.3.3-1.el6 will be installed
–> Finished Dependency Resolution

Dependencies Resolved

=============================================================================================================================
Package                        Arch                       Version                            Repository                Size
=============================================================================================================================
Installing:
php-mcrypt                     x86_64                     5.3.3-1.el6                        epel                      18 k

Transaction Summary
=============================================================================================================================
Install       1 Package(s)

Total download size: 18 k
Installed size: 46 k
Is this ok [y/N]: y
Downloading Packages:
php-mcrypt-5.3.3-1.el6.x86_64.rpm                                                                     |  18 kB     00:00
warning: rpmts_HdrFromFdno: Header V3 RSA/SHA256 Signature, key ID 0608b895: NOKEY
Retrieving key from file:///etc/pki/rpm-gpg/RPM-GPG-KEY-EPEL-6
Importing GPG key 0x0608B895:
Userid : EPEL (6) <epel@fedoraproject.org>
Package: epel-release-6-8.noarch (installed)
From   : /etc/pki/rpm-gpg/RPM-GPG-KEY-EPEL-6
Is this ok [y/N]: y
Running rpm_check_debug
Running Transaction Test
Transaction Test Succeeded
Running Transaction
Warning: RPMDB altered outside of yum.
Installing : php-mcrypt-5.3.3-1.el6.x86_64                                                                             1/1
Verifying  : php-mcrypt-5.3.3-1.el6.x86_64                                                                             1/1

Installed:
php-mcrypt.x86_64 0:5.3.3-1.el6

Complete!
[root@s16960602 ~]# service httpd restart
Stopping httpd: [  OK  ]
Starting httpd: [  OK  ]