The Swagtron T1‘s maximum weight limit is 220 lbs or 100kg. This is the official numbers, so I suspect there is a significant safety margin in there. You could probably get away with riding it at 250 lbs, but if it gets damaged or you get hurt, the company would not be liable.
There is also a weight minimum at 44 lbs or 20kg. Small children should not attempt to ride hoverboards!