Images can't be compressed into any arbitrary size.
You can optimize the file size against the image quality, but you can't shrink a file size into just any size you want. How small you can make a file depends on the type of information it has (photo vs. line art) and any features about the image data that can be taken advantage of in by the various formats.
If you want advice on how you can best optimize the image you have, post the image and someone can offer you concrete advice.
well you could make it only 5kb but whether or not you have a recognisable image at the end of it would be a surprise