The 2019 ford ranger has a6 x139.7mm bolt pattern on them. this means that you have 6 lugs and they are 139.7mm away from each other. when you get new wheels make sure that they fit this size exactly. there are adapter plates on the market, but they can cause damage to the wheel hub or the new wheel. usually a reputable wheel shop will be able to give you a selection of wheels to fit your truck. in general you should not go more than two inches larger in wheel diameter as that can lead to rubbing when you turn. going too large with tires and wheels can also damage the gearing in your truck.
Im sure he knows they're 6 lug, the bolt patterns 6x5.5 or 6x139.7
The 2019 ford ranger bolt pattern is 6 lug.
What about the thread size