How can I correct errors in invoice details like tax rate, state etc before filing GST return?

To correct errors in invoice details like tax rate, state etc before filing GST return, you need to follow steps: 
 Step 1: Go to the Display menu and click on GST report, then GST return, and select GSTR1 E return. 
 Step 2: Define the date range and click on the OK button, Four windows will appear, and three of them will be for checking possible errors. 
 Step 3: You need to click on all three error buttons - Check error in transaction, Check error in HSN summary, and Check error in document summary. 
 Step 4: If any errors appear in red color, correct them according to the error description. 
 Step 5: Once you have corrected the errors, you can generate GSTR1 successfully. If the issue still persists on the GST site, 
 Step 6: download the error report from the website and also download the offline tool from the GST site's download section and install it. 
 Step 7: After opening the offline tool, click on the last column to upload the error report, which will show specifically in which row the error is occurring. 
 Step 8: You can correct it in BUSY data and then upload or generate GSTR1 successfully.