Proper positioning of begin transaction and commit transaction

Is the positioning of the begin try and begin transaction and end try and commit transaction correct? I ask because I sometimes get a message about transaction count being wrong with previous count being 0 and current count being 1.

CREATE PROCEDURE [dbo].[rbs_RevalidateQuote]
      @I_vQuote_Number INT,
      @I_vSequence_Number INT,
      @I_vQuote_Date DATETIME
AS
BEGIN
      
      SET NOCOUNT ON

DECLARE @TranCount int
DECLARE @ErrMsg nvarchar(4000), @ErrSeverity int

SET @TranCount = @@TRANCOUNT

IF @TranCount = 0
      BEGIN TRAN UpdateRevalidateNumber
ELSE
      SAVE TRAN UpdateRevalidateNumber

DECLARE @REVALIDATE_NUMBER INT

-- Get the current highest revalidate number
SELECT  @REVALIDATE_NUMBER = CASE WHEN MAX(REVALIDATE_NUMB_OEQH) + 1 < 9 THEN max(REVALIDATE_NUMB_OEQH) + 1 ELSE 9 END FROM CSTQUTHD WHERE QUOTE_NUMBER_OEQH=@I_vQuote_Number AND
      SEQUENCE_NUMBER_OEQH=@I_vSequence_Number

BEGIN TRY
      
              -- Update quote header
            UPDATE CSTQUTHD
            SET REVALIDATE_NUMB_OEQH = @REVALIDATE_NUMBER,DATE_OF_QUOTE_OEQH=@I_vQuote_Date,INACTIVE_OEQH=0,CST_QT_PRT_DATE_OEQH='19010101' WHERE QUOTE_NUMBER_OEQH=@I_vQUOTE_NUMBER AND
                  SEQUENCE_NUMBER_OEQH=@I_vSequence_Number

            --      Update quote lines
            UPDATE CSTQUTLN
            SET REVALIDATE_NUMB_OEQL = @REVALIDATE_NUMBER,CUST_QT_DATE_OEQL=@I_vQuote_Date WHERE QUOTE_NUMBER_OEQL=@I_vQUOTE_NUMBER AND SEQUENCE_NUMBER_OEQL=@I_vSequence_Number

            -- Update quote kit lines
            UPDATE CSTQUTKT
            SET REVALIDATE_NUMB_OEQK = @REVALIDATE_NUMBER,CUST_QT_DATE_OEQK=@I_vQuote_Date WHERE QUOTE_NUMBER_OEQK=@I_vQUOTE_NUMBER AND SEQUENCE_NUMBER_OEQK=@I_vSequence_Number

            -- Update quote note lines
            UPDATE NOTELINE
            SET REVALIDATE_NUMB_OQNL = @REVALIDATE_NUMBER WHERE QUOTE_NUMBER_OQNL=@I_vQUOTE_NUMBER AND SEQUENCE_NUMBER_OQNL=@I_vSequence_Number

END TRY
BEGIN CATCH
            ROLLBACK TRAN UpdateRevalidateNumber
            SELECT      @ErrMsg = ERROR_MESSAGE(),
                        @ErrSeverity = ERROR_SEVERITY()
            RAISERROR(@ErrMsg, @ErrSeverity, 1)

END CATCH

-- Complete the transaction
COMMIT TRAN UpdateRevalidateNumber
END

GO