I searched a lot regarding the Data Matrix Code generation from Nav 2015 but could not get any proper solution for that though, i got some code from below link but still, some of the automation variables is not there in Navision, so I need you guys help on this, is there any Code Unit or any object or any other way in Nav..
It depends on how much time you have to get the barcode.
If it's a back end job, like a report, you can call a command line tool to create the barcode and import the generated image file into a BLOB of a table variable. This table field is then printable within the report.
Another way I use in production is running a web service that creates the barcode and then let Navision create a web page that is opened in a browser window..