Interest on late payment of gst

Prashant Agrawal (20 Points)

10 January 2020  
suppose i have filed my april gstr 3b on 30 august. however i have not submitted interest on same amount till now (ie 10 jan 2020 ) and , gross output liability is rs 60000 and Itc available was rs 30000.

my question is how much interest i will have to pay today??