It would be something along these lines:

DECLARE @MyTableVar TABLE

(

empcode nvarchar(300)

);

BEGIN TRANSACTION

BEGIN TRY

-- Update master table

INSERT INTO EmployeeMaster.....

OUTPUT INSERTED.empcode INTO @MyTableVar

-- Update child table

INSERT INTO EmployeeDetail (empcode, other fields...)

SELECT empcode

FROM @MyTableVar

INNER JOIN .... other tables as required

-- Commit the transaction if successful

COMMIT

END TRY

BEGIN CATCH

-- Rollback transaction if unsuccessful

ROLLBACK

END CATCH