what type of reagent required to convert so^2 to s?

A strong reducing agent, such as burning magnesium and hydrogen sulfide, is needed to reduce SO₂ to S.
The relevant equations are:
2Mg(s) + SO₂(g) → 2MgO(s) + S(s)
2H₂S(g) + SO₂(g) → 2H₂O(l) + 3S(s)

a reductant. reducing agent. Something that will give up electrons to S and lower its charge from +4 to 0. that substance itself gets oxidized in the process, of course (SO2 acts as an oxidant, an oxidizing agent).

What is 'so^2'
Do you mean sulphur dioxide (SO2)

In which an iodide solution will reduce to 'S'.

The kind that someone who has there masters in math would know.