I took a look at the PennDOT rules online, and it looks like it isn't doable. There are some exceptions, the Roxor could be a type A vehicle (<10,000 lbs GVW) if you are a farmer. You are limited to a 50 mile radius and only for certain purposes such as traveling between farm properties, or taking the vehicle in for repair. And you can only drive it on the "highway" from sunrise to sunset. You have to be a real farmer, providing tax forms as proof. And this assumes that they will let you get an exemption for a vehicle that is deemed off-road only by the manufacturer. The website below uses the word farm truck and farm vehicle, but who knows what that means to a bureaucrat?
Another route that would require a lot of work is buying a junk Jeep, combining parts from it with the Roxor, along with whatever you need to get up to minimum street legal for the year of Jeep you have, and use the VIN of the junker to get a reconstructed title. Keep all your receipts, they want to make sure you paid sales tax on everything when you go to get the title. And the vehicle must go through an enhanced inspection, working from the premise the reconstructed vehicle was badly damaged and needs to be checked carefully, so you can't just send photos and hope they won't notice that it is a Roxor in disguise. Plus proof of insurance, in either case.
Since I'm not a lawyer, the second route may be total nonsense, but it seems to be what the online documents say, and seems similar to what other states require.
Titling Registration and Exemption
https://www.dot.state.pa.us/Public/DVSPubsForms/BMV/BMV Fact Sheets/Reconstructed_Vehicles.pdf
Doug