No, the person will not be allowed to pay tax under the composition scheme for the remainder of the year if they cross the turnover of Rs. 1.5 Cr in the month of December. According to the composition scheme rules, if a taxpayer exceeds the turnover limit of Rs. 1.5 Cr during the financial year, they are required to opt out of the composition scheme from the date on which the turnover exceeds the limit. Therefore, the person will have to pay tax as a regular taxpayer for the remaining period of the financial year, i.e., till 31st March.