How to use yum without use rhn in red hat?

How can i use yum in red hat without using rhn?

RedHat is subscription based so their repositories assume you have registered on RHN.

You CAN setup local repositories if you have the RPMs you need but in general use of "RedHat" implies use of RedHat's repositories.

If you want Redhat like software but don't want to pay for a subscription to RedHat you should use CentOS instead as it is a binary compile of RHEL sources. You can use CentOS repositories without paying a subscription.

You should NOT try to use CentOS repositories on RedHat. Many of the RPMs will work due to the fact they're compiled from the same source but there are differences in the rpm database between the two systems. Either use RedHat and pay the subscription or use CentOS instead - don't try to mix.