TCS applies to specific transactions: sale of liquor, scrap, minerals, motor vehicles above ₹10L, and most importantly for ecom, marketplace facilitator TCS u/s 52 of CGST Act (1% TCS on net consideration paid to ecom sellers) and Section 206C(1H) of Income Tax (0.1% TCS on goods sales above ₹50L).
For Indian D2C sellers on marketplaces, the marketplace deducts 1% TCS from your sales proceeds. This appears in your GSTR-2A and is claimable in your GST returns. The 0.1% income tax TCS appears in your Form 26AS.
TCS reconciliation is a monthly chore for marketplace sellers — match what each marketplace deducted, reclaim in GSTR-3B, and ensure 26AS shows correctly for income tax credit.