My buy order in Bracket order is executed but, now i want to cancel the Bracket Order. Can I?
After the execution of your Bracket Order(BO), you will only be able to exit the BO position. Only open unexecuted orders can be cancelled.
Lets assume you placed a Buy BO. You can quickly exit this BO position by finding the Bid Price from the Market Depth window and modifying your Sell Limit target order to a price slightly below this Best Bid Price and your BO position will be squared off.