Hi Sri,
Sadly, Apple does not support WebRTC on iOS.
The BigBlueButton HTML5 overview
states
Google Chrome on Android devices support WebRTC (we use these devices for development and testing); however, Apple's Safari browser on iOS devices does not. It would be great if Apple were to support WebRTC -- or to enable other browser to use their own rendering engine on iOS -- but until then we (and you) are restricted to using the HTML5 client platforms that support WebRTC.
In other words, Safari iOS =! Chrome Android for rendering engine or support for WebRTC. What's more, in iOS, Apple restricts browser manufactures to use their rendering engine, which means Chrome iOS =! Chrome Android.
As a result, the HTML5 client will not run on the iOS devices -- without WebRTC, there is no audio or video sent or received. We looked at using HLS (HTTP Live Streaming), but thats more for streaming a recorded file as the lag is about 10-15 seconds. In a live class, we felt the lag is too much.
We are working on a iOS solution for BigBlueButton, but, for now, our priority is to finish the first release of the HTML5 client first.
Regards,... Fred