Correct order of reactivity towards nucleophilic addition in the following compounds is

Aldehydes are more reactive than ketones towards nucleophilic addition.

Explanation :-

I) Steric hindrance on carbonyl carbon is lesser in aldehydes.

II) Electrophilicity of carbonyl carbon is more in aldehydes Lesser the +I groups (alkyl groups), more the electrophilicity of carbonyl carbon.

$\therefore$  III is least reactive

EWG (NO₂) increase the reactivity towards nucleophilic addition 

EDG(-CH₃) decreasethe reactivity towards nucleophilic addition.

Reactivity :

II > IV > I > III