Please try this,

create procedure [dbo].[USP_Reliance_Master_Upload]

as

begin

--declare @dt datetime , @Mnth varchar(10)

------ If the data consist of Mnth column data as null or blank values

IF EXISTS (SELECT 1 FROM Ram_Reliance_Master where ISNULL(RTRIM(LTRIM(Mnth)), '') = '')

RETURN -1

BEGIN TRY

IF EXISTS (SELECT 1 from Ram_Reliance_Master

WHERE DCPI_Date = convert(varchar(10),convert(datetime,DCPI_Date),101) )

RETURN -1-- The Date Field is In Correct Formate so Please Check Your Data

END TRY

BEGIN CATCH

RETURN -1-- The Date Field is In Correct Formate so Please Check Your Data

END CATCH

insert into dbo.Reliance_Master

(Mnth,DCPI_Date,GRP_OUTS_RIL,Interest_Cost,OverDue_Earned,Qty,EPI,insertDt,Year)

select

Mnth,convert(datetime,DCPI_Date),GRP_OUTS_RIL,Interest_Cost,OverDue_Earned,Qty,EPI,cast(getdate() as DATE),DATEPART(YY,DCPI_Date)

from Ram_Reliance_Master

end