Hi Saranya

Contiki is an open source operating system for the Internet of Things. Contiki connects tiny low-cost, low-power microcontrollers to the Internet. Contiki is a powerful toolbox for building complex wireless systems. Contiki runs on a wide range of tiny platforms, ranging from 8051-powered systems-on-a-chip through the MSP430 and the AVR to a variety of ARM devices. There are also a number of more exotic platforms thrown in there for good measure.

This link may help you to control nodes,

http://xmpp.org/extensions/xep-0325.html

The following links will be useful for your research..

http://www.silabs.com/Support%20Documents/TechnicalDocs/Internet-of-Things-System-Design-with-Integrated-Wireless-MCUs.pdf

http://www.controleng.com/single-article/distributed-controls-in-the-internet-of-things-create-control-engineering-resources/fb0eea6e0b9d0d8cd97aad4025e5c080.html

http://www.azosensors.com/article.aspx?ArticleID=705

http://xmpp.org/extensions/xep-0325.html

http://www.iec.ch/whitepaper/pdf/iecWP-internetofthings-LR-en.pdf

https://yourstory.com/2015/03/internet-of-things-application/

It's perfectly possible using different approaches. IOT has more flexibility for node extension.