Configure
the maximum number of co-authoring authors in SharePoint 2013
Description: The CoauthoringMaxAuthors property lets you specify
the maximum number of users who can co-author a Word document or PowerPoint
presentation at the same time in SharePoint 2013. This article describes how to
configure the CoauthoringMaxAuthors property by using Windows Power Shell.
Check the ink below from MS.
http://technet.microsoft.com/en-us/library/ff718248%28v=office.15%29.aspx
I hope the above information will help you to resolve the issue, in case of any queries/questions regarding the above mentioned information then please let me know. I would be more than happy to help you as well as resolves your issues, Thank you.
