Arunprasath,
I should have been more specific. What I was wondering was where specifically within Business Portal the fields were located. If you're referring to some of the querying capabilities of Business Portal, you can modify the column names within the queries so that your desired name is displayed to your users. This is a simple change within the modify query wizard.
If they're located within one of the features like Requisition Management, Project Time and Expense, etc., you can modify some of the labels. This isn't something that would be upgraded moving forward, but it would be a simple change within the aspx pages.
Thanks
Rob