Very little I suspect.  When this news item was aired on the regional BBC news programme"Look East" their public sample  unanimously "had never heard of him".  There are streets named after Robert Kett; most people who have attempted to cycle up Kett's Hill will remember the hil at least.  Bowthorpe, now a sprawling housing development, was the last staging  post for the advancing rebels before their arrival in Norwich,  There is nothing there now to commemorate that historical connection. Schools here don't include  Kett's Rebelllion in their history syallabus, which is a sad loss.  Norwich has a fine tradition of medieval sedition, which is largely lost on its present population.

It's odd that this should be so, because there is great interest in local history, but it's largely restricted to what is still in living memory, and  available in pictorial record.