i got the status :not subscribed when i registed

HI EVERY BODY

please help me ,i don t know what to do now .
i downloaded from the red hat site installed red hat 7 and i succeeded to registered and subscribed also.
but my boss told me that he wants redhat 6.3 or 6.4. so i reinstalled the red hat 6.3 but now when i registered
i get the status: not subscribed.
i followed some advices on redhat site and read some forum about this but nothing to do i am not able to get status :subscribed.
please help me