Hello, 

To identify/Check Active Directory FSMO Roles, you have multiple ways:

# Run below command on command prompt.

     NETDOM QUERY FSMO

# OR Run below command on command prompt.

   ntdsutil
   roles
   connections
   connect to server DC-name
   quit
   select operation target
   list roles for connected server

After verification, Type quit until you have exited from Ntdsutil

# OR Run dcdiag /test:knowsofroleholders /v command on command prompt.

Hope it helps you.