I have search on Google but didn't get proper example how to create Text chat application using webRTC and node.js .
Please if anybody knows how to do this .please share details .
Since webRTC uses peer-to-peer communication, you may not need node.js to make the chat.
However, you may use node.js to do the signaling to set up the communication (using Websockets for example). Once you have the RTCPeerConnection up and running, you can use the RTCDataChannel to send text.
The link below may get you started