How do i make a category and keep posting under that category in all/selected websites

How do i make a category and keep posting under that category in all/selected websites?

I want to add a link - say "For Patients" to appear on menu bar of all websites which is a category link of all heart related topics - this is possible i know (manually have to do it)
then How do i post a post at once in all these blogs under this category? is it possible?