Is there a way to convert FLA or SWF into SVG format? It can be a Software? Or even a Web convertor? I have tried a few things and none of them worked. All of them seems out of
No. There are too many features that SWFs support and that the SVG format does not for it to be able to create a valid version of the SWF.
If you just want the symbols, you can open/import/paste them into Adobe Illustrator and then save it as SVG. That'd work. You lose all SWF functionality and advanced features, of course.