Q.79 Where shall Supply made to merchant exporter i,e @ 0.1 % , be reported in GSTR 1 & GSTR 3B as its not deemed export under GST .
Ans As you have mentioned, the outward supply is not deemed export then supply made to merchant exporter to be treated as normal B2B supply, thus in GSTR-1 details of supply made to merchant exporter to be shown under Table- 4A.
GSTR 3B contains summary of outward supplies, inward supplies liable to reverse charge, eligible ITC, payment of tax etc. Thus, it does not require invoice-wise data of outward supplies. Hence, it would be shown under Table- 3.1(a)- Outward Taxable Supplies.

Q. 78 If Mr. A make sale to Mr B for Rs. 100000+18000(GST) and after sale Mr. A give discount to Mr. B by credit note of Rs.10000, but GST reversal not made. Now product cost to Mr. B of Rs. 90000 and Mr. B sold its product for Rs.95000+17100 (GST). Mr. B claim Input of Rs. 18000 and not paid in cash and Rs.900 still shown in credit ledger or can use for other sale. In that case profit shown in books but still Mr. B not paying GST in cash. Even excess balance in credit ledger. Is Mr. B need to pay 1800 GST (on Rs.10000) even not reverse by Mr. A.
Ans Commercial credit note is not governed under GST law and is issued only for the value of discount/ reduction in value of the supply, without any GST.
Post supply discounts are governed by the provisions of clause (b) of sub-section (3) of section 15 of the CGST Act, discounts that are given after supply is made and are allowed as deduction from the value of supply if the following two conditions are satisfied: –
1. Discount is as per existing agreement, and
2. Proportionate ITC is reversed by the recipient.
If the above conditions are not satisfied, commercial credit note can be issued.
In the above case scenario, credit note given of Rs. 10,000/- is termed to be commercial credit note. And Mr. B is not required to reverse any ITC.
However, the subsequent transaction of Rs. 95000 is inconsistent w.r.t previous transaction because of not declaring GST credit note and can lead to litigation.

Q. 77 Is it required to generate e-way bill in case unregistered buyer cause the movement of goods and if yes, reference of particular legal provision?
and also intent of second proviso to sub rule (3) of rule 138 of CGST Rules.
Ans Under GST regime, as per sub-rule (2) of rule 138 of CGST rules, if goods are transported by the registered person whether in his own conveyance or hired one or public conveyance, by road, the registered person shall have to generate the e-way bill.
However, if the sub-rule (2) is not followed then sub-rule (3) comes to place.
Coming to second proviso to sub rule (3) of rule 138 of CGST Rules, if the movement is caused by unregistered person either in is own conveyance or a hired one then either unregistered person or the transporter may generate the e-way bill in the manner prescribed.

Yes, e-way bill is required to be generated in case the movement of goods caused by unregistered person.