Are those jets that can be seen in The Man in the High Castle when Joe Blake travels to Berlin for real? For a second I thought they were like Concordes but then I realised they were not. If no, then the VFX used is really great.
There were only two commercial SST, the Concorde and the Tupolev Tu-144.
This is neither of those, the tails and cockpit windows are different, and the Nazi aircraft has fewer exit doors than the real-life aircraft.
So, it's a Special Effect (CGI)
Here's a shot of the effect actually being filmed
There is a YouTube video from Zoic Studios who do the effects. This can be seen at 1.14
The last Concorde airbody is currently at Aerospace Bristol, a museum dedicated to the region's involvement in air travel, in the UK.
No, it's not a real plane, it's CGI.
The design looks like a hybrid of the rather famous Concorde
& the less famous & rather more crash-prone Tupolev TU-144
Perhaps a case of 'parallel evolution' or even just 'spying'.
Both planes first flew in 1969.
Germany already had the jet engine in the mid-40s (in our timeline ;) as a parallel evolution to the Whittle engine developed by the Allies, before & during the war.
The Messerschmidt Me 262 saw service before the end of WWII.
Let's just assume the show's writers saw fit to bring that development forward a little - it helps shorten the wait between character moves very nicely.