Can I get a re-entry permit with a single entry tourist visa (TR visa) in Thailand?

Yes, you can buy a re-entry permit on a single entry tourist visa 60 day stamp, you can get it at the immigration office that serves the area where you stay or at the airport before you fly out

Remember though, a re-entry permit doesn't add any more days to your stay, your current stamp still expires when it expires, you just can exit/re-enter and get stamped back in until that date.

Take the PDF print out with you (that is your visa) when you apply for the re-entry permit