Can I swap 15 inch tire an rim with a 16 inch tire an rim?

The rims an tires are off a dodge van, they are 5 hole rims, the car I want to put them on is a ford taurus with a 16 inch tire on it.

No. The bolt patterns have to match and the rim itself needs to be big enough to clear the brakes. Not to mention tire width.

Not all 5 hole patterns are the same, even within brands sometimes. For instance, I had some Chevy pickup rims that were 5 hole, and I wanted to put them on my Impala (5 lug) but they wouldn't fit.

After you check THAT out, about all you can do is put one on and see if it clears and doesn't rub anywhere.

You need four characteristics to see if the rim will fit: bolt pattern (5 x 72 deg), center circle diameter, bolt size, wheel offset. Once that is cleared, you can install bigger rims following the rule: one step up in diameter (15" to 16") requires one step down in aspect ratio, e.g. /60 to /55.
In this manner the rolling circumference will remain within approx. 3 percent of the old one, meaning the car will handle predictably, brake and accelerate correctly and keep the odo and speedo accuracy within limits.