As noted check door jamb sticker if you have one. Absent that, Oasis report will tell you oem size. Ford may tell you "Research Div" although I've found for old trucks they don't know much.
Following may help, although Note it is '97 brochure info, probably same for '96.
For XLT:
Standard: P195/70R14SL BSW Diam 24.8"
With either pref eq pkg: P225/70R14SL OWL Diam 26.4
Optional: P235/60R15SL BSW Diam 26.1
Those are all season tires, no all-terrain tires offered for 4x2, naturally.
If 225's were oem, you would have indeed got deep dish aluminum wheels with that (in '97 anyway) as part of the pref eq pkg. In '96 the deep dishes were optional. Steel wheels were standard. Full face chrome was also optional.
I'd say do what the other guys said and get the 15" wheels and put a set of Coopers on them, that's a decent tire. I have that brand on the Mazda and they seem good. NTB has them.
Since 235's are almost the same diameter as what you have on there would be minimal change to power, ride height, or the speedo. You can check the speedo vs gps speedo app on your phone to see what it's reading now.
The 235's would be nice for highway on the 15" wheels, you wouldn't have to change out the spare, because the diameters are almost the same not only that you don't have the problem of 4x4 possible binding on the highway. Not sure if you have lsd, but even if you did you can drive for a while on a slightly mismatched diameter. Note there is a max size you can fit in the spare carrier so it might not even be possible to have the spare the same size if you go to 235/60.
Obviously I'm assuming bolt pattern is the same 14" or 15".
Or if you want to save money and just stick with the 14", you can get nice Coopers for them too.
Shop 225/70R14 Tires | NTB
I have had decent luck with local NTB but it's just a suggestion, point it, you can get the tires for what you have, or you can, as recommended, part with some dollars and upgrade to 15". Maybe you could recoup something from the 14" aluminums you have now. Junkyards might have some 15" wheels, and if you're really trying to save money maybe you just go to basic steel wheel, those should be cheap at j-yard or ebay etc but the aluminum deep dish are of course much prettier.
Depending on what you like, 15" with less sidewall probably is a nice look and handling for a street truck. If it was off road, I prefer taller sidewall with more flex to it, but that's not an issue for you.
Here's the '96 brochure
1996_ford_ranger_brochure.pdf (therangerstation.com)
It looks like the same specs except the aluminum wheels were optional not part of pref eq pkg as in '97 as mentioned above.
To me since you can still get the 14" tires, you can get away with maybe $600-$700 for a set of 4, mounted. Maybe you want to replace the spare if it's lousy, as mentioned.
To go to 15", won't change the tire cost much if any, but you'd have to add something ($300?) for a set of 15" aluminum deep dish wheels (ebay). Not a huge increment especially considering 14" is getting rarer. And it would look good, handle good, and -if- the speedo was calibrated (gear) to the 225's, it should still be real close to correct.
Don't forget tires wear so their diameter changes over time anyway that's why the speedo specs have a range. My feeling is in general you don't want it reading low (or much high either) because if you drive 4mph over limit, which normally no one will stop you for, and your speedo reads low, you could be going 8mph over the limit then you could get stopped.
My 2 cents. Open to argument or criticism.