The balance amount of integrated tax remaining in the integrated tax account in respect of the supply for which an apportionment to the Central Government has been doneunder sub-section (1) shall be apportioned to the,––
(a) State where such supply takes place; and
(b) Central Government where such supply takes place in a Union territory:
Provided that where the place of such supply made by any taxable person cannot be determined separately, the said balance amount shall be apportioned to,––
(a) each of the States; and
(b) Central Government in relation to Union territories,
in proportion to the total supplies made by such taxable person to each of such States or Union territories, as the case may be, in a financial year:
Provided further that where the taxable person making such supplies is not identifiable, the said balance amount shall be apportioned to all States and the Central Government in proportion to the amount collected as State tax or, as the case may be, Union territory tax, by the respective State or, as the case may be, by the Central Government during the immediately preceding financial year.