that is not where you install it
please use YUM
it will install ALL needed dependencies and install it to the correct location
also CentOS 6.2 is unsupported !!!
please upgrade to the only 6 version that is supported
yum --releaseserver=6.3 upgrade
the centos6.2 repos are DEAD
yum search gcc
that will output what is in the repos that you have installed
you also need a LOT of other things besides just gcc
you NEED the whole suite of tools that gcc needs to work
---- will output a list of "software groups "---
yum groupinstall "Development Tools"
then after that we can look into any needed extra software