Demand raised for interest on short payment of tax

during fy 2018-19, the Company has failed to declare the correct gst liability and result short payment of tax. but subsequently, once identified, the same has been discharged in the coming months.
at the same time, there was balance lying in the credit ledger, but the same was not sufficient to meet the gst liability.
Can the department charge interest on gross liability, or interest will be charge on net gst after utilizing the credit balance.
and also the department can issue SCN for the year 2018- 19.
pls let me confirm