Local Datum and Spheroid in Al Ain, UAE       

 Local Geodetic Datum : Nahrwan (NAH_B), 1967
 Reference Ellipsoids: Clarke 1880
Semi-major axis: 6378249.145 meter
Inverse flattening (1/f): 293.465
Projection: UTM
Zone: 40
Centeral Meridian: 57 degree East and 54 degree East if Zone 39.
Scale factor: 0.9996

Convert from UTM to WGS84 shift X by 120 meter and Y by 420 meter.