In my application the master cannot be directly connected to the wireless communication device hence, I have two micrcontroller where the slave is interfaced with the wireless device and the data will be sent or received at any point of time through SPI protocol.
The slave is interfaced with wireless communication device and the master has to receive the data from the slave. And if the master wants to sent the data through wireless it has to send it to the slave. All the sequences happen asynchronously i.e. the data can be sent or received at anytime.
I don't really understand what's going on, but if what you want is bidirectional communication between two devices which may be initiated by either side, wouldn't some form of duplex serial interface be more suitable? If you're trying to make an SPI slave initiate a message to the SPI master, I can't see that working.
As an aside, how certain are you that the 'master' can't be connected directly to the 'wireless communication device'? You seem to be facing considerable complexity and I wonder whether it's necessary.