MakeMKV will "make MKV files". It's kind of the name of the program.
If you're looking to just "make a VOB file", that's different.
MakeMKV decrypt VOB file
Re: MakeMKV decrypt VOB file
MakeMKV Frequently Asked Questions
FAQ about BETA and PERMANENT keys.
How to aid in finding the answer to your problem: Activating Debug Logging
FAQ about BETA and PERMANENT keys.
How to aid in finding the answer to your problem: Activating Debug Logging
Re: MakeMKV decrypt VOB file
If the DVD is a true disk, you can put it into your drive and make an ISO with MakeMKV. The current versions support creating a decrypted ISO backup of DVDs (not of BluRays/UHDs though).