Set map region in iOS Mapkit

.m File

 CLLocationCoordinate2D location;

   location.latitude=yourlatitude;
   location.longitude=yourlongitude;

   span.latitudeDelta=0.01;  //or whatever zoom level
   span.longitudeDelta=0.01;

   region.span=span;
   region.center=location;

   [mapview setRegion:region animated:TRUE];
   [mapview regionThatFits:region];

Alternative

 MKCoordinateRegion CSC;
    
    // Defines the center point of the map
    CSC.center.latitude = 33.874809;
    CSC.center.longitude = -98.521129;
    
    // Defines the viewable area of the map. Lower numbers zoom in!
    CSC.span.latitudeDelta = .003;
    CSC.span.longitudeDelta = .003;
    [map setRegion:CSC animated:YES];