Can I convert it to a raw video ?
No, if you don't record in raw, you can't get back to it. That's why people go through the headaches of recording in RAW. RAW is the actual photosite exposure data and isn't actually a usable image on it's own. Imaging sensors don't pick up all colors on each individual pixel. Some pixels pick up red, others blue, others green. Some fancy designs may have one or more other colors as well.
The data about the values of each of these photosites (each of which will eventually be a pixel) is fed in to an algorithm that looks at neighboring pixels and figures out the RGB value for each pixel. During this calculation, the information about the original values is lost and only the RGB pixel values are kept.
On some sensor designs, it might still be possible to work backwards if you had full bit depth RGB data (though many can't), full understanding of the filter and conversion logic and avoided certain exposure situations, however you have an additional problem that the video has been put through one or more rounds of compression in addition to being stored in a color format that does not preserve the full bit depth of the color data.
This means that the necessary color information does not exist anymore no matter if your particular camera happened to use an algorithm that was reversible (which is itself unlikely).
Practically speaking, there is no way to get back to RAW from a processed video. If you want to work in RAW, you need to start in RAW.
If you don't have an option to work in RAW and are trying to maximize your color correction ability, shoot with the highest color depth you can and shoot log color to avoid losing information in the brighter and darker areas. You'll end up with a little bit less color information in the mids of the finished product, but it will buy you a ton of room for tone adjustment in post (and if you are able to shoot 4444 and are editing to a final output of 422 or lower you probably won't lose a ton anyway.)