HOW TO DISCLOSE RCM IN GSTR 9 paid after FY

DEAR EXPERTS,
One of my client paid RCM on Freight in Sep 2018 for the year 2017-18.
Where it Should be disclosed in GSTR-9 Annual Return.
 
As per my understanding: – 
A. Where we should Report IT

1. We should report it in Table 4 (G)
2. It should be included in total tax payable  in Table 9

B. Things Creating Problem: – 

1. In Table 9 you can not amend TAX PAID
2. If we report it in Table 10 then it will increase our Total Outward supplies and Tax on outward supplies to be reconciled in GSTR-9C.

 
Now the question is how to disclose that we have already paid this Tax in sep 18.