Its not very clear what you are trying to accomplish, but here is my interpretation of your code in the correct T-SQL
syntax.
I'm not prepared to guess what you're trying to do below that.
CREATE TABLE tblBookInfo
(
AccessionNumber NVARCHAR(MAX),
RandomNumber NVARCHAR(10),
AccNo NVARCHAR(MAX)
)
DECLARE @Upper INT,
@Lower INT,
@RandomNumber INT
SET @Lower = 1 SET @Upper = 9999
SELECT @RandomNumber = Round (((@Upper - @Lower -1)* RAND() + @Lower), 0)
SELECT @RandomNumber