WhatsApp and Facebook tops 1B active users

1. WhatsApp and Facebook have 1B active users:  http://www.recode.net/2016/7/20/12232130/facebook-messenger-one-billion-users
2. Facebook Tops WhatsApp in India:  http://www.livemint.com/Industry/vU55FbKdlz9vIfkxUb0EoL/Facebook-tops-networking-WhatsApp-in-message-apps-in-India.html
3. India Internet Population: http://www.internetlivestats.com/internet-users/india/

 Here are some theories. 

•  The majority of Whatsapp and FB Messenger users come from India.Let us assume 50% of each messenger apps; that is a cumulative 1B active user coming from India, which is not possible because there is only 462M people have access to the internet. 
• Out of 462M, practically everyone in India should be using both FB Messenger and WhatsApp messenger. If so which one is the most actively being used? Should we use messages sent per month as a KPI?
• 1M messages sent per month from FB Messenger is pretty low, 1 message per user, what is the definition of an active user then?

Somewhere something is incorrect. There is no doubt that these two messaging platforms are great, and India loves both FB and WhatsApp. However, we need to see more distilled numbers to know what exactly is going on?