Assuming you are planning on staying in NZ while your residence application is considered, then you have to remain lawfully in NZ and on a valid temporary visa until such time as your residence is approved. An application for residence doesn't remove that obligation to remain lawfully in NZ by having a valid visa.
You need to lodge a further temporary based visa on or by 30 May.you can though simplify the application by relying on the information lodged with the residence application, but still need application and sponsorship form. You may be able to rely in medical and police clearance if they are not more than 3/2 yeas old at time you lodge application.
It possible but unlikely that your residence would be approved in just 2 months