Disclosed Quantity is a feature which allows only a fraction of the order to be viewed by the market.  Example., If you want to buy /sell 10,000 shares of Axis Bank, you can place an order by defining DQ as 1000 shares. 1,000 shares of Axis Bank will be available for buying/selling in the market, once executed, the  next lot of 1000 shares of Axis Bank will be displayed. 

This will continue till the full quantity is exhausted. This helps when the quantity to be bought /sold per scrip is very high. Huge quantity may disrupt the balance of demand and supply and the price may increase/decrease towards/against your favor. In order to avoid such erratic changes in the price, it is advisable to place an order with DQ.