i am at fresher level,i want to know about the Grunt server is able to handle production application deployment.
.. please help me.
Yes, you can. But to do it would be madness. So... I'd say no, don't do it.
A Grunt "server" (in quotes because it actually runs on top of NodeJS) is only meant for local development. However, Grunt runs on NodeJS, and with the help of some frameworks like ExpressJS you can get something to work on NodeJS. See this Deploying a production Node.js server.
Grunt is a task runner, it's meant to help one develop faster. But Grunt won't deliver production-ready builds every time you run tasks. It will help you get there by letting you know what you need to fix to get a production-ready build. When you do that - and only then - you may release the latest build. Combine it with a version control tool like Git and you are covered.
Make sure you are self-employed before serving live Grunt builds on a production server, so you don't loose your job... :)