Vihaan, a registered person under GST, supplied goods amounting to 1,18,000 (inclusive of GST, taxable @ 18%) to Trihaan, a registered person under…

Vihaan, a registered person under GST, supplied goods amounting to 1,18,000 (inclusive of GST, taxable @ 18%) to Trihaan, a registered person under GST on 30th September. Trihaan further sold such goods to Eyaan, a consumer who came to his shop on 30th October in cash, for 2,36,000 (inclusive of GST, taxable @ 18%). Vihaan issued a credit note of 11,800 (₹ 10,000 +1800 - GST) for rate difference on 2nd November to Trihaan. Thereafter, Trihaan entered a credit note in its books for the same amount in the name of Eyaan, without intimating him and providing any refund of the sum paid, on 2nd November and reduced its output tax liability accordingly. As per the provisions of GST law, which of the above-mentioned suppliers are allowed to reduce their output tax liability?