Note: All ASMLib installations require that the 'kmod-oracleasm','oracleasmlib' and 'oracleasm-support' packages be installed on the system. The 'oracleasmlib' and 'oracleasm-support' packages are available for download at the locations listed below.
The kernel driver package 'kmod-oracleasm' is available directly from Red Hat, and can be installed from the "Red Hat Enterprise Linux Server (v. 6 for 64-bit x86_64)" channel on Red Hat Network (RHN). Use the ASMLib kernel driver that corresponds to the version of the Red Hat Enterprise Linux kernel you're running.
To identify which version of the ASMLib kernel driver you need, view the description field of the 'kmod-oracleasm' package on RHN.
Also, see the release notes.