Taʾwil: selecting a permissible non-apparent interpretation on relevant evidence.
Takhsis: excluding some members of a general class through qualifying evidence.
Naskh: superseding an earlier legal ruling by subsequent authoritative revelation.
These are not interchangeable concepts. Taʾwil concerns which meaning is intended, takhsis concerns the extent of a general ruling, and naskh concerns the continuation of a ruling over time.
The distinction makes clear exactly which possibilities remain or are excluded at the levels of nass, mufassar and muhkam.