6 letter words:
fortis9,
5 letter words:
first8,
foist8,
forts8,
frist8,
frits8,
frost8,
rifts8,
riots5,
roist5,
rosit5,
rosti5,
rotis5,
tiros5,
torsi5,
trios5,
trois5,
4 letter words:
firs7,
fist7,
fits7,
fort7,
fris7,
frit7,
fros7,
orfs7,
rifs7,
rift7,
sift7,
soft7,
orts4,
riot4,
rits4,
rost4,
roti4,
rots4,
sori4,
sort4,
stir4,
tiro4,
tori4,
tors4,
trio4,
3 letter words:
fir6,
fit6,
for6,
fro6,
ifs6,
oft6,
orf6,
rif6,
sif6,
ios3,
iso3,
its3,
ors3,
ort3,
rit3,
rot3,
sir3,
sit3,
sot3,
sri3,
tis3,
tor3,
2 letter words:
if5,
of5,
io2,
is2,
it2,
oi2,
or2,
os2,
si2,
so2,
st2,
ti2,
to2,