If we want to create User ID in System, How can we assign the same user ID to different User in Linux
Raja please use appropriated titles: http://www.daniweb.com/community/rules
This is the fifth thread you start with the same generic title.
I'm not sure why you'd want to have duplicate user IDs offhand, but it is possible:
Using the -o option with commands like useradd, adduser and usermod will allow you to use duplicate/non-unique UID's.