what is the difference between worked and have worked?

I always get confused with worked/have worked/had worked/have been working
If I want to say `I have worked in Japan for 6 years`,but I dont work there anymore,is it correct way to say it?
or i have to use`I worked in Japan for 6 years`? what if I say `I have been worked in Japan for 6 years` ,whats the difference with `have worked` and `had worked`~

Shafqat pretty much has it. "I worked in Japan for 6 years" only refers to the past, and "I have worked in Japan for 6 years" most likely refers to an ongoing situation.  Some native speakers may still say "I have worked in Japan for 6 years" in response to a question like "What sort of experience do you have working overseas?" However, if you say "I have worked in Japan" without the "for 6 years" it will only refer to a past situation.

"I have been worked..." is incorrect and should be "I have been working in Japan for 6 years." This only applies to an ongoing situation.