Reduced interest for delayed GST returns: conditional nil interest if GSTR-3B filed by specified extended deadlines. Provides conditional reduction of interest for FORM GSTR-3B filers for specified tax periods in early 2020 by prescribing differentiated interest rates and extended filing deadlines based on aggregate turnover. Relief is available only if the return is furnished within the corresponding extended deadline set for each turnover class and tax period; the mechanism specifies class of registered persons, rate of interest, tax period, and the conditional filing date that triggers nil or reduced interest.