Showing excess itc balance..how to reverse?

Hello sir,

How can i reverse my ITC balance as it shows me a very big amount of ITC balance in SGST (about 88,22,919) which should be 0.

There is a mistake done by me as I had entered wrong input in Eligible ITC (SGST Tax about 8837074 instead of 88370.74) and also filed my GSTR-3B return for that month.How can I change or reverse my ITC balance to 0.? 

I have also contacted to helpdesk and they had suggested me to enter the amount in Eligible ITC -> ITC Reversed -> and there are two options (a) & (b).If this is the solution, can you suggest me where should I enter my amount to reverse it, (a) or (b).?

Thanks & Regards,

Meet.