The issue of revised invoice is in order, if it meets the requirements under Section 31 of the CGST Act, 2017 and Rule 53 of the CGST Rules, 2017. Regarding the e-way bill, I believe the goods reached the destination within the validity of the original e-way bill. In that case, it was neither necessary nor in order for you to generate another e-way bill merely on the grounds that the HSN code mentioned was incorrect. Error in 4 or 6 digit level of HSN where the first 2 digits of HSN are correct and the rate of tax mentioned is correct is a condonable lapse, as per CBIC Circular no. 64/38/2018-GST, dated September 14, 2018. With effect from November 16, 2018, GSTN has enabled e-way bill system not to allow the consignor/supplier, consignee or transporter to generate duplicate e-way bills against the same invoice.