Hello team,

I have a redhat 5 dvd. I want to know the bit of OS like x86 or x64 bit. How I will know that. Please help me.

If you are browsing through the DVD navigate to Packages directory and check if kernel package ends with x86_64 or with i386 or i686. If it ends with x86_64 it is 64 bit, if it ends with i386 or i686 then it is 32 bit.

also keep in mind that the current legacy support RHEL 5 is RHEL 5.11
it is great on OLD legacy hardware
if you are not using server hardware that is 10+ years old
it is advisable to download and BUY $$$ the required support contract for RHEL 6.6 or 7.0

"RedHat Enterprise Linux" really is not free
for a server install the standard and REQUIRED contract is $799 per year
for a single DESKTOP install it is $399 per year

if you are NOT going to buy the required contract
DO NOT USE RHEL!!!
instead install the FREE rebuild of it
CentOS 6.6 or 7.0
or CentOS 5.11 for old( 10+year old) legacy hardware