in-place interface problem
 

I used in-place interface between the porous region and fluid region for my problem. I even initialized the interfaces. But there is no connectivity between the slave and the master faces.

could any one tell me the reason?

Just a guess, maybe imprint the interfaces and try it again! If there is no gap between these interfaces there should be a connection

You can check an interface by eye. As you pick it in the model tree the faces are highlighted with a color so that you could see if they are right or not. Besides, check a tolerance value within your interface.