mistake in vat return

Now, you can rectifiy your mistake at the time of making VAT R2. because Vat R2 required consolidated summry of Vat R1 and sales figures as per your P & L A/c. You are just required to make a reconcilation of your diff. with Sales A/c of Your Books and attach with Vat R2 and last date of filling VAT R2 is 31 Oct of the Asstt. Year.