Oh dear. So much poor advice. On behalf of solar system imagers, I apologize for the misinformation, Milos. But you're in the right forum now.
First, AutoStakkert tells me 80% or so of your 1790 frames are above the 50% relative quality criterion. So I'd proceed to stack 80% of them, in this case.
However, the issues really lay with the raw (or in your case, not raw, but slightly 'cooked') image data.
Firstly, your focal length (hence f-ratio) is significantly too short. Jupiter is only covering 40-something pixels in the image. And the captured data is already RGB, compromising resolution further.
Jupiter should be at least three times that diameter. You need to be using at least a 3x barlow to get good data.
I know, even using a 2x is giving you an even more blurred image. There could be several reasons for this, primarily SEEING. The atmosphere is rarely steady at the scales we image at. But some times will be better than others. The second contribution to blurring is the low elevation of your target. The only way to partly counter that is to use an ADC in your imaging train, particularly as you're using a one-shot color camera. As pointed out above, focus MAY also be an issue - I can't really tell due to the scale of the data provided. And you need to make sure your reflector is as well-collimated as is humanly possible. Focusing on a larger target is also easier than focusing on a really small target. Use the belts, GRS or festoons to determine the optical focal point on Jupiter.
Using AutoStakkert to stack is just fine (desired, in fact). But try to stack thousands of frames, not just a few. I see your frame rate was 19fps. That's awfully low - that will also lead to smearing. And it will take you a while to build up a few thousand frames. In fact, at that rate, I would recommend recording for 180 seconds at a time. Even that would only get you around 3400 frames, so most of those better be good ones!
Registax can be used for color tweaking, wavelets (deconvolution) and resizing.
I like your enthusiasm and drive to succeed at this. You WILL get better. If you were to change just one thing requiring money, I would upgrade your camera to a ZWO or QHY. That would give you the biggest bang for your buck, as they say.