GSTR-3B filing deadlines set with staggered regional and turnover-based extensions; payment via electronic ledgers required. Specifies that FORM GSTR-3B for October 2019 to March 2020 is to be furnished electronically through the common portal generally on or before the twentieth day of the succeeding month, subject to multiple provisos granting later filing dates for specified States, Union Territories and for taxpayers below a turnover threshold; and mandates that tax, interest, penalty, fees or other amounts must be discharged by debiting the electronic cash or credit ledger not later than the last date for furnishing the return.