Of course, the content depends greatly on the circumstances of the fermentation: How warm was it? How much preparation liquid was used? How much sugar was used? And most importantly, how long was it fermented?
Our kombucha in the shop, for example, has a residual sugar content of 3.6 g per 100 ml. As a rule of thumb, you can say that after 7 days about half of the sugar is metabolized.
If you want to have less residual sugar, ferment longer instead of reducing the amount of sugar from the beginning. You should use at least 60 g of sugar per liter, otherwise the fermentation can be lame...
The sour Kombucha can be diluted with water, tea or juices.