Caravans

Full IoM Government details about Caravans is here > https://www.gov.im/categories/travel-traffic-and-motoring/caravans/

The TT Grandstand is an approved campsite for the duration of the event, if you wish to extend your stay (pre or post event) then you need to use another approved campsite outside of the event dates.

Also have a look at Accommodation you might find it is cheaper/better to stay in a small hotel then bring your caravan?