According to Le cha telier's principle when we increase the pressure of a equilibrium reaction the reaction shift to the side where few moles of gas present.
Your reaction (Notice - I guess the reaction you written is wrong, but still I'm solving with your given prediction)
3NaI (g) + H2 (g) = 2NaHI (g)
Where access of sodium iodide is reacting with Hydrogen gas to form NaHI molecule.
Number of moles of gas on reaction side - 3+2 = 5 moles
Number of moles of gas on product side - 2 moles
Conclusion- the reaction will shift to the right of the reaction
