I'm not positive, but I think that NO2 is a stronger deactivator bc there is a positive charge on the N. The argument for meta/op directors is a resonance where in one of the resonance forms, a positive charge will lie on the carbon attached to the functional group if attached o/p. Both SO3H and NO2 are electron withdrawing, so having a positive charge next to them is unstable. Therefore they are both meta directors. However, NO2 is worse, bc that would mean there are two positively charged atoms adjacent to one another.
Because NO2 is a stronger deactivator, SO3H would direct in any further reaction.