@pranksterguru I guess you've misunderstood trades somehow. So, If an order is executed, and it is large, it may execute in a single or multiple trades. Since the order is rejected by the system, no trades are registered as the order is never sent to the exchange but is rejected by the EMS (execution management system) for any number of reasons.
do we get any other data in this webhook postback?
You will come across these order status often i.e. open, executed, rejected and cancelled. For more info about other status, try fetching individual executed order as mentioned here. It will give you lifecycle of an order in our system.
why arent the trades that i bought through kite web interface is not returned in API?(holdings or positions)
For more info about other status, try fetching individual executed order as mentioned here. It will give you lifecycle of an order in our system. You do get positions and holdings.