Safe harbour for business income attribution sets profit thresholds, restricts deductions, and limits loss set-off for eligible assessees. Safe harbour is available for income attribution from eligible business or profession where an eligible assessee exercises the prescribed option and the declared income meets the specified gross receipt thresholds for raw diamond or storage of components in a custom bonded warehouse. If the option remains valid, specified deductions are treated as fully given effect to, depreciation is reflected in written down value, and set-off of unabsorbed depreciation, carried-forward losses, or other business and head-wise losses is not allowed against income from the eligible business.