install latest git on centos 6.4

First of all you need an rpmforge repository installed on your system. Than you should enable rpmforge-extras repo.
yum provides git
In output you will find something like

Loaded plugins: fastestmirror, presto
Loading mirror speeds from cached hostfile
* base: ftp.colocall.net
* epel: ftp.colocall.net
* extras: ftp.colocall.net
* rpmforge: apt.sw.be
* rpmforge-extras: apt.sw.be
* updates: mirror.mirohost.net
rpmforge | 1.9 kB 00:00
rpmforge-extras | 1.9 kB 00:00
rpmforge-extras/primary_db | 452 kB 00:00
git-1.7.6-1.el6.rfx.x86_64 : Git core and tools
Repo : rpmforge-extras
Matched from:

git-1.7.8.2-2.el6.rfx.x86_64 : Git core and tools
Repo : rpmforge-extras
Matched from:

git-1.7.11.1-1.el6.rfx.x86_64 : Git core and tools
Repo : rpmforge-extras
Matched from:

git-1.7.6.4-1.el6.rfx.x86_64 : Git core and tools
Repo : rpmforge-extras
Matched from:

git-1.7.7.4-2.el6.rfx.x86_64 : Git core and tools
Repo : rpmforge-extras
Matched from:

git-1.7.1-2.el6_0.1.x86_64 : Fast Version Control System
Repo : base
Matched from:

git-1.7.10.1-1.el6.rfx.x86_64 : Git core and tools
Repo : rpmforge-extras
Matched from:

git-1.7.10-1.el6.rfx.x86_64 : Git core and tools
Repo : rpmforge-extras
Matched from:

git-1.7.6.1-1.el6.rfx.x86_64 : Git core and tools
Repo : rpmforge-extras
Matched from:

git-1.7.3.4-1.el6.rfx.x86_64 : Git core and tools
Repo : rpmforge-extras
Matched from:

git-1.7.11.3-1.el6.rfx.x86_64 : Git core and tools
Repo : rpmforge-extras
Matched from:

git-1.7.10.4-1.el6.rfx.x86_64 : Git core and tools
Repo : rpmforge-extras
Matched from:

git-1.7.9.6-1.el6.rfx.x86_64 : Git core and tools
Repo : rpmforge-extras
Matched from:

git-1.7.1-3.el6_4.1.x86_64 : Fast Version Control System
Repo : updates
Matched from:

git-1.7.1-3.el6_4.1.x86_64 : Fast Version Control System
Repo : installed
Matched from:
Other : Provides-match: git

To install latest git just type

yum install git-1.7.11.3-1.el6.rfx.x86_64