I bought this PDF with this ab training program and it says for incline twisting situps “2 sets – 12 reps, 8 reps, 10 reps” I don’t know what it means. Do you think it means 2 sets of 12 reps, 2 sets of 8 reps, and 2 sets of 10 reps?

A "rep" is short for "repetition" which means one action, in this case one rep = one sit up.

I don't know either. Contact whoever sold you the PDF and ask them.

I can't Eileen G, whenever I send them an email they don't reply.

What is the set and rep range for the rest of the exercises? If two sets is standard, then it's unlikely you have to do six sets for this exercise. I've got to say, the numbers are very odd, I've met a lot of exercise plans, and I've never seen that rep pattern.

The 3 sets is standard, but some of the other ab exercises are isometric(hanging leg raise is like 20 seconds).

But a sit-up is a movement, not isometric.