What It Means
A GTC (Good Till Cancelled) order is a globally common order type that stays live on the exchange's order book until it either executes or you cancel it — with no expiry date.
How It Works
Indian exchanges don't actually support true GTC — every pending order, filled or not, is auto-cancelled at the end of each trading day. That's an exchange-level rule, not a broker limitation, so no Indian broker offers real GTC.
Note
What Indian brokers offer instead is GTT (Good Till Triggered) — it doesn't sit as a live order on the exchange at all. It sits with the broker and only gets sent to the exchange once your trigger price condition is actually met, and typically stays valid for up to a year.