how to install Oracle 11gr2 in RHAL 6.4?
there is no operating system called that
there IS RHEL6.4 ( Red Hat Enterprise Linux 6.4)
Read the install instructions from Oracle !
And if you NEED Oracle's server class database it would be wise to
1) Use the current 12g
2) install it on Oracle's rebuild of red hat " Oracle linux 6.4"
-- it is built and configured and optimized FOR running Oracle's DB