Upgrading Scientific Linux 6.3 to 6.6

<p> </p>   <span>I have to update my test machines from SL6.3 to6.5.I tried # yum list updates and # yum update .It downloaded some files and installed .But my SL is still showing SL6.3 and # yum list updates returns "Loaded plugins: refresh-packagekit,security".</span><span>Is there a way to upgrade it from6.3 to6.6 using terminal?</span>