Convert RAR to MPEG

It is unlikely some way how to convert RAR archive to MPEG or any other video format directly, i.e. something that rar to mpeg conversion represents. In case you meant that you want to extract MPEG movie from a RAR, you need to decompress it using WinRAR or similar program.

Simply put, it is impossible to convert RAR to MPEG directly.
Thus, there is no so-called rar to mpeg converter or a free online .rar to .mpeg converter to be found.