Co-authoring in SharePoint enables multiple users from different geographic locations works on a single document simultaneously.This can be achieved by activating versioning in doucment library settings. Once you enable the versioning, execute the below powershell commands to enable Co-Authoring in SharePoint 2013.
$site="https://mysite:4040"
$currentSite=new-object Microsoft.SharePoint.SPSite($site)
$currentSite.WebApplication.WebService.CoauthoringVersionPeriod = <Time To Update>
$currentSite.WebApplication.WebService.Update()
*<Time To Update> is in minutes