Normally you would want to use yum to install packages, including Samba client and/or Samba server. If you have a subscription for your Red Hat instance, this is a no-brainer. If not, you can use the EPEL repository (How to use Extra Packages for Enterprise Linux (EPEL)? - Red Hat Customer Portal), find Red Hat compatible RPMs on the net, or try using CentOS repositories (haven't done this in a while so not sure of the latest status).