i have water in oil. have changed head gasket but it did not correct

Could be a number of things... Was the head and block deck surface checked for warpage before going back together? Also could be cracked cylinder head or even cylinder wall (not as common). I If the vehicle has an oil cooler that is cooled by the engine coolant, this could be another source for a leak, although it will get oil into the cooling system as well due to higher oil pressure than hot coolant pressure when the engine is running.