Not really. There is a 125cc shifter class not a stock moto class. It gets between 0 and 3 entries.
Most popular classes are lo206, Yamaha senior and masters, and tag sportsman. If you haven’t raced in a while I would recommend tag sportsman to start along with tag heavy. The specs are the same for both so you can use the same kart and setup and race twice.
If you are a lighter guy, tag lite gets good entries.
Here is a link to the different classes at newcastle.