Every dealer liable to pay tax under the Act, who before the commencement of the Act had been doing business, shall, within thirty days of the commencement of the Act, submit to the concerned assessing authority a return in the form prescribed under rule 21AA showing the total turnover and taxable turnover of his business separately in goods liable to different rates of tax, in the financial year immediately preceding the commencement of the Act. He shall also submit a return in Form 10 showing his estimated total turnover and taxable turnover for the first twelve months of his business.