i hv filed my Gstr1 march-19 . but missing some invoice in Gstr3b and tax not paid as per Gstr1. can i paid this tax in GSTR3B Apr-19 or paid this tax at the time of Gst audit 18-19.
Yes, you can pay it in April 2019. It's better you pay it in the April return, so that you will have to pay lesser interest than if you pay it at the time of annual return filing.