I need to know if there is any OpenSource kiosk software, which i can use to run my custom desktop based application, to run on a POS (Point of Sale).
Yes, there's lots. Actually it doesn't need any custom software - it's just a specific configuration of the OS. There is a kiosk extension for Firefox. Here's a description of how to set it up using a bootable CD / Ubuntu, here's one using the Chrome browser, there's a puppy image too - and there's lots more on Google.