The taxable event under GST is supply.
Section 7 : Meaning and scope of supply.
Section 8 : Taxliability of Composite and Mixed Supplies.
Schedule I : Activities to be treated as supply even if made without supply.
Schedule II: Activities or transactions to be trated as supply of goods or supply of services
Schedule III: Activities or transactions which shalll be treated as neither supply of goods nor as supply of services.