Wrong GST Input Credit

Excess input should be shown as input reversal column in next month's 3B. ITC can neither be claimed nor can be reversed in annual return. In case you miss out on reversal in 3b you can do so through DRC-03 as well.

Best method for you right now will be to reverse such itc through DRC-03.

Interest on reverseal is applicable

Either you can report the excess ITC in annual return or reverse the excess ITC through DRC 03

There are 2 way out to reverse the excess ITC claimed:
1. Reverse it in your Subsequent GStR 3B (which can be declared in annual return)
2. Or File DRC 03 & Setoff from credit or cash ledger.

Note : In my view as ITC excess claimed is pertaining to march (previous Fy ) So should reverse by Filing DRC 03 , because if you reverse it by reporting in subsequent return you need to prepare Reconciliation Statement for Both the Year.

You can do in both ways i.e.

1. Either Reverse it in next month GSTR-3B
2. Or Reverse it by submitting DRC-03.

To communicate with assessing officer,he will issue an intimation ,u may use DRC 3,and blocked in next 3B.

No Reverse methods in GST.
But u may make an arrangements in 3 B March 2021(for the period from April to Sept and October to March till September 2022 on the invoice validity periods.