Missing sales fy 2018-19 gstr 9a

Ramesh patel (Business) (190 Points)

29 March 2020  
a trader in composition scheme ,dealing in both exempt and taxed goods, misses to show exempt good sales like rice/pulse in gstr quarterly return for fy 2018-19 , upon entering missed sales in annual return does trader is liable to pay tax on exempt sales , if yes what is penality for it ?