10 April 2020
For the month of March 2018, i have claimed IGST input instead of CGST and SGST. Now in April 2020 while filing annual return for 2018-19 it came to knowledge.
11 April 2020
Yes, reverse the wrong ITC claimed in your return. Pay the CGST & SGST liab with interest if the IGST input was set off with any outward tax liability.