dinesh s Please attach/double check your config.json file to see if details provided there are correct.
Furthermore , Did you make the required changes to index.js in thingworx-nodejs-agent/thingworx-agent-examples/examples/three/ folder.
Make sure the the "exampleThing” variable is set to the name of the Remote Thing that you created earlier (i.e. “HomeLight0”).
Dinesh ,where is your Thingworx platform running ? on local laptop (on which IP changes very frequently ) or on server where IP is fixed , the catch is , when you put the ip of machine on which thingworx is running in config.json , and you change your network( from office to home or vice -versa ) , IP changes and you have to counter that changes in config.json file .