@ naveen ji, it's being decided in 26th GST council Meeting, plz refer to that first
for Ur kind information: The present system of filing of GSTR 3B and GSTR 1 is extended for another three months i.e., April to June, 2018 till the new return system is finalized. A new model was discussed extensively and Group of Ministers on IT has been tasked to finalize the same.