Input tax credit distribution: proportional allocation by turnover with ISD invoices and GSTR-6 reporting required. ISD must distribute Input Tax Credit monthly and report in FORM GSTR-6, separately allocating eligible and ineligible credits and treating integrated, central and State/Union territory tax credits distinctly; distribution to recipients is by a proportional formula based on each recipient's turnover, with debit and credit note adjustments apportioned and reflected in the month of inclusion, and prescribed ISD invoices and credit notes issued for distributions and reductions.