Hi Mohan,
If you can pull all the issues you want to close into a view, perhaps with a report if they aren't already available in a single view, you can easily select all of them and bulk-edit by clicking the Edit button at the top of your list of issues and changing the status to closed - as long as those issues weren't converted to a project or task with their resolution tied to that other object.
I don't know of any way to auto-close an issue other than converting it to a project or task with its resolution tied to that object.