GTT is an order you place in RYZ MARKET (buy a scrip at a particular price) and wait for it to execute based on the conditions you have entered.
GTT Order is essentially a trigger order that is placed and maintained on RYZ MARKET and when the set price is reached your order is sent to the exchange for execution.
For example, if a stock is currently priced at Rs. 500, then you can place a GTT order to buy the stock when the price reaches Rs. 400 . So when stock reaches Rs. 400, then the order is triggered and sent to the stock exchange for execution - either at Market Price or Limit price.