Hello Achappan,
I'm in the process of upgrading to Moodle 2.9, and am investigating whether the badges system (which has been in Moodle since 2.5, I think) could replace my home-grown certificates system. The only thing it seems to lack is a good admin dashboard for showing who has which badges, though I might just be missing something.
If you haven't already, you might want to look into whether it could meet your needs. You can definitely create a badge that requires that the user has passed an arbitrary set of classes.