When editing the Publisher Layouts, the option "override the predefined actions" is missing. Is there a way to locate this option?

Hi Ashwin,

Make sure Chatter Publisher is enabled 

1. From Setup, enter Chatter Settings in the Quick Find box, then select Chatter Settings.
2. Click Edit.
3. Select Enable Actions in the Publisher.
4. Click Save.

Hope this will help you

Thanks

Piyush