Yes, the following two types of discounts would be excluded from transaction value:
Discount at the time of Sale – Allowed as a deduction, provided if the discount is recorded on the face of invoice. Post-supply Discount – If such discount is based on the arrangement entered into before or at the time of supply, AND where the same can be linked to relevant invoices, then the same is allowed as a discount on the condition that the recipient reverses the input tax credit related to such discount availed earlier.
(ICAI FAQ PUBLICATION 06-09-2017 VALUE OF TAXABLE SUPPLY: FAQ NO. 53)