I Got solution for customised workspace with rulers bar saved with it.
What we can do is if we want our customised workspace with ruler bar saved to it, So We can create document with your custom sizes according to dimensions needed. For example, create document related to business card dimension or any other dimension you would like and click create. Remember: It should be the blank artboard with nothing on it. Do not create any artwork on it before saving it as illustrator .AIT template. It will create document of that size. After that go to view, rulers, show rulers. Then click save as and choose the format as Illustrator template file that has extension of .AIT
After that choose your location to desktop or wherever the location you prefer and save that file.
Done. It will permanantly saved your workspace with rulers bar added to it. That is it. Make a seperate folder named as workspace template on your desired location.
Doing this way you can also carry this customized workspace in pendrive or other storage device as well.
Everytime go to your folder where the saved file or template is and click twice to open the file and choose illustrator from all the option given. That is it. It will open with customized workspace you did with the rulers bar. By that way we do not have to click rulers every single time when we work on the document.