CREATE TABLE [dbo].[postaltable](
	[postalcode] [varchar](50) NULL,
	[city] [varchar](50) NULL,
	[state] [varchar](30) NULL
)

GO


INSERT [dbo].[postaltable] ([postalcode], [city], [state]) VALUES 
('11000', 'shimla', 'HP')
,('22000', 'dehradun', 'UK')
,('33000', 'noida', 'UP')
,('44000', 'panjim', 'Goa')
,('55000', 'Agra', 'UP')
,('66000', 'Jaipur', 'Rajasthan')
,('77000', 'Rampur', 'UP')


Go
  
CREATE function [dbo].[demofun] (@str varchar(100))
 returns @colDetails table 
 (
    postalcode varchar(50),
	city varchar(50),
	state  varchar(50)
 )
begin
DECLARE @strXML AS XML
SET @strXML = cast(('<test>'+replace(@str,',' ,'</test><test>')
                 +'</test>') AS XML)

insert into @colDetails 
select * from postaltable where city in 
(
   SELECT A.value('.', 'varchar(max)') FROM @strXML.nodes('test') AS FN(A)
)
return
end

GO



select * from [dbo].[demofun]('Agra,Jaipur')