Determination of income in the case of non-residents.

10. In any case in which the [Assessing Officer] is of opinion that the actual amount of the income accruing or arising to any non-resident person whether directly or indirectly, through or from any business connection in India or through or from any property in India or through or from any asset or source of income in India or through or from any money lent at interest and brought into India in cash or in kind cannot be definitely ascertained, the amount of such income for the purposes of assessment to income-tax [* * *] may be calculated :—

(i) at such percentage of the turnover so accruing or arising as the [Assessing Officer] may consider to be reasonable, or

(ii) on any amount which bears the same proportion to the total profits and gains of the business of such person (such profits and gains being computed in accordance with the provisions of the Act), as the receipts so accruing or arising bear to the total receipts of the business, or

(iii) in such other manner as the [Assessing Officer] may deem suitable.