You can find the number of active users in the Viva Engage(Yammer) Networks in the below ways.

1. Via Apps4.Pro Migration Manager
   
   Step 1 : Navigate to Plan tab -> Reports. Please choose the Source / Target Network Users under ‘Yammer’ section to get the respective users.
   
   
   
   Step 2 : Choose one or more networks
   
   
   
   Step 3 : The active & the pending users part of the chosen networks are listed.
   
   
   
   
2. Via Viva Engage(Yammer) Admin Center
   
   
   1. Login to Viva Engage(Yammer) Admin Center : https://www.yammer.com/office365/admin.
   2. Navigate to Users -> Export Users. You can choose to export all users / export users in a particular time period. The list of users are exported in a CSV format.