Sims 3 won't recongize my gtx 1660 ti (I have tried everything)

@Furiosa2727  The edited graphicscards.sgr is fine, as your deviceconfig reports that the card is "found."  It's the "matched" part that's not working, and that's from graphicsrules.sgr.  Here's the issue:

or match("${cardName}", "*GT 16??*")

Make it GTX instead of GT.  If that alone doesn't help, you can change 16?? to 1660 ti as well, although it shouldn't be necessary.

While you're at it, you may want to tell the game that your card has an appropriate amount of VRAM, or texture memory as TS3 calls it.  Change this, eight to ten lines down:

if ($textureMemory == 0)
  seti textureMemory       32
  setb textureMemorySizeOK false

to this:

if ($textureMemory == 0)
  seti textureMemory       1024
  # setb textureMemorySizeOK false

So you're changing the 32 to a 1024 and putting a # and a space in front of setb.  Even though your card has 6 GB of VRAM, the game can only use 800 MB.  The value is also in the deviceconfig, a few lines below the found and matched values.