Gst annual return filing

No... it's not mandatory.

Wait for Notifications.
Moreover as per Rule 62 , inserted by Notification ,20/2019 CT , require to furnish a return for every Financial Year in Form GSTR-4 till 30th day of april following the end FY

So need to File GSTr 4 annually

As a composition scheme dealer can I file drc 3 for voluntary payment of difference in tax
what are consequences if I file before any order or intimation ?

Composition Scheme Dealers are not required to file FORM GSTR-9A for FY 2017-18 & FY 2018-19.

As per 37th GST Council, it is decided to completely waive off the compliance of filing FORM GSTR-9A for FY 2017-18 and FY 2018-19. But "Removal of Difficulty Order" u/s 172 of the CGST Act 2017 to give effect the above decision is not yet issued by the CBIC.

What's difficulty order? sorry didn't get it

As per Section 172 of CGST , the Government given power to Amend the Act by issuing RoD.