That's a kind of complicated issue. It depends on the base item you are going to gamble for.
When gambling, an item has an item level of character level - 5 to character level + 4 which goes into a calculation that leads to a value called affix level. With that range of item levels, have a look at this item affix generator
(don't worry about it saying that it's for patch 1.11, nothing has changed in that respect since then), select the item you want to gamble for and on the next page enter the item level you are going to check out, press OK and scroll down. The "level" column is the affix level, by the way.
As the item level for gambling is a range, you will have to find a compromise with high rolls on it leading to a few affixes with a level requirement beyond 9 and low rolls with a selection of affixes that is missing a few that are close to the top end.