I recently read through NVIDIA's TNT2 datasheet stating that Windows NT 3.5x would be supported as well. Though I have not seen any such drivers floating around. Have a gander here:

http://www.o3one.org/hwdocs/vga/RIVA_TNT2.pdf.pdf

Malik wrote:

Here are some of the graphic cards' drivers for Windows 3.1/3.11 and Windows NT 3.51. […]
Show full quote

Here are some of the graphic cards' drivers for Windows 3.1/3.11 and Windows NT 3.51.

The drivers for Windows NT 3.1 are harder to find.

I have uploaded them as individual files, since these files are more specific in use, and one may not need to download everything in one bulk.

I still have zipped them all up for archival purposes. I'll post the link to the full archive once Megaupload is ready with the file.

This is an on-going project. All contributions of files are welcome and I'll keep updating as I get more files.

Link : Windows NT 3.51 Graphic Cards Drivers

Link : Megaupload Full Single Archive File

Mirrors, Courtesy of WolverineDK :

Mirror 1 - http://www.multiupload.com/LOX0RQLH2A

Mirror 2 - http://www.megaupload.com/?d=KDSKY6AN

Edit : Lists edited for legibility.

Note : Since I have only used some of the cards listed here, I'm unable to test all the drivers for full functionality. Kindly take note. Thanks!

Great upload Malik but it seems over the years both links and mirrors appear to be offline/dead.
Have these been moved to a new location or can you reupload the Win 3.1 and NT drivers again?

Unfortunately, the drivers are no longer available here which is a pity!!!

For nVIDIA RIVA 128 and TNT/TNT2 under Windows 3.1x you may try those drivers:
Re: Windows 3.11 - nVidia TNT2 built-in GPU chip compatibility