When we do Edit Connection of Data Source on Tableau Server, It provides options to edit below details.
1. Server Name
2. Server Port
But we don't have option to change Service Name or Database Name (considering my datasource is build using Oracle Database).
Please let me know if i am missing something.
You are not missing anything, the Service Name and Database Name are not currently editable via Tableau Server.
I recommend voting on this Idea on the Ideas forum to voice your support for adding this feature in a future release: