Like this then:

USE [GFD_DB]
GO
/****** Object: StoredProcedure [dbo].[ORC_N]  Script Date: 24/07/2017 21:46:11 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
ALTER PROCEDURE [dbo].[ORC_N]

  @CurAno INT,
     @ORCN int OUTPUT
    
    
AS

BEGIN TRAN

    SET NOCOUNT ON;
  UPDATE dbo.Numerizar WITH(TABLOCKX, HOLDLOCK)
    SET @ORCN = ORCM += 1
    WHERE AN = @CurAno;
 
COMMIT TRAN