"how can i design some thing that is acceptable in most parts of world."

You will have to research the call progress tones for relevamt telco for your target markets; eg, UK (BT) information can be found at http://www1c.btwebworld.com/sinet/

eg, the British Ring Tone goes "Ring..Ring........Ring..Ring........" whereas the American Ring Tone, I believe, goes more like "Riiing..........Riiing.........."

Then you will have to come up with some scheme to support all these variations, and some way for your users to select their "Country configuration"

I have used Lookup Tables to good effect in such applications

Not a complete solution I know but, as Dan said, "this outline should get you started."