Is there any method by which the Region Code can be changed to Region Code 0 which plays all Region Codes?
No, there is no method which would allow you to change this settings always.
Of course you can find many different tips in the world wide web how to overcome such settings but I would not recommend trying this. In most cases people say that an firmware update is needed but an usage of such incompatible firmware would damage the CD/DVD driveā¦so its definitely not recommended.