Your question goes back to the old, old, old unsolved argument of which is better; Nikon or Cannon.
It is still unsolved.
As for lenses:
The T3i can handle all EOS lenses
The D3200 can handle all lenses, but it will not autofocus on the older lenses that require a focus motor built into the camera. All of the newer lenses have focus motors built into the lens.
Either way there are more than enough lenses available.
Get your hands on both cameras and buy the one that feels right to you.