(1.6.1) and it works fine but i would like to understand the reasons and diffrences
and if i am able to delete the first one(1.6.2) or it will effect the installed one
thanks
The instructions you linked to were for building from source; yum installs a binary package. As to why building from source didn't work for you, the instructions you linked to are wrong.
As for deleting the one you built, you have to do make uninstall to remove it, and yes, you need to do that, because it will conflict with the binary package you installed.