If you have Magix Rescue Your Video Tapes 6 Version 4 it should be windows 8 compatible. If you have Rescue Your Video Tapes 4 it is not even on the windows 8 list. See this link
Realistically, if the product that you have is not currently Windows 8 compatible, I seriously doubt that it will become so at a future date. Remember that we are not Magix technical support, we are a user forum, so if you want more information on this, you need to contact Magix support.
I bought Video Saver 4.0 about 6 or 7 years ago and I was going to try it now in 2019 on Windows 8.1. It did not work. It seems that I have to buy a newer version of this software.
Did you notice you had posted to a thread which is nearly five years old? Although I accept your post is at least partially relevant to the OP, please do not resurrect such old posts.