How many unpaired electrons are in a low spin fe3 + complex high spin complex?

The terms used (high-spin and low-spin) doesn’t refer to a number of unpaired electrons but to different electron configuration in d-orbitals that you can get from the pairing energy. As for Fe3+’s unpaired electron here are the answers:

Octahedral high-spin: 5 unpaired electrons

Octahedral low-spin: 1 unpaired electron