I am not too sure what archive are you looking at but you can find most of such settings under Settings > Advanced

I mean how do we set the conversations to archive to X days.
As I am looking for the settings to set conversation to archive.

As you had a archive modules in the http://stackideas.com/docs/easydiscuss/administrators/menu-layouts/archives-layout but i cannot the option to set to archive

It's not possible to archive conversations in EasyDiscuss currently

I thought the archive module is available and the setting should be there.

Currently that was not possible at this point of time.