•Created one repository "rep_1" and shared a project "krty" with vuser name"Search".[Now revision number in repository changed as 1]
•Later I renamed the vuser “Search” as "Search_product" and I updated it. [Now revision number in repository changed as 2]
•Now I want to checkout revision 1 from the repository. How it is possible???
[If I tag the project then it is possible for me to checkout. I want to know is there any other way without tagging]
You did the right thing. If you would like to keep a specific version of your project you have to tag it.
There's no other option to get back to a specific revision other than that.