Can i add some extra channels to my Avionics RCB 7X Radio?please suggest me some methods.  

IF you want to go to more than 7 channels, then buying a new radio would be the straight forward solution. 

What exactly are you trying to do, and why do you need more channels ?

Adding a channel to the receiver is possible but dont know about the rcb7x
I have seen somewhere one guy has added a 5th channel to a 4ch GWS R4P receiver by just soldering a signal lead at pin11 of the IC located at the front side Also, And also a positive and a negative lead from the receiver now the three wires will form the extra channel..
But you need extra care while working with pre made electronics as they may useless when modifications go wrong..
I Will surely go through The way that anwar suggested.. 

http://www.rcgroups.com/forums/showthread.php?t=19362

That is a receiver only mod, and still requires a radio that is capable of transmitting information for more than 4 channels.

In this case, looks like the OP is looking for changes to the transmitter itself, which is asking for a LOT !

Anwar bhai I think We can make it possible to add a channel to the transmitter...
Let me check As i read about this some time.. I am not able to recollect the website..

There are cases where this has been done.  The recent and well known example is that of the Futaba 8FG (http://www.rcgroups.com/forums/showthread.php?t=1395875).  But those additional channels may not be useful for all purposes, and they are triggered with programmable mixes etc, hence the question about what the intended use is. 

On top of that, there is need for updated firmware to support the added channels. Overall, this looks like a tall order.

Yeah...
shyam first you must reveal your intentions behind this.. So that only someone can help you...
If a channel can be added to this radio then why cant rcbazzar do it and get more popularity..?

RCB7X RADIO have flap system but i dint find any individual switches for it.It works only  as programable mixes with other  controls. It also has  a 3 way toggle switch,so can i use that switch individually for flap control,or can i modify that switch 

Before that, why were you looking for more channels ?  Flaps seem to have nothing to do with additional channels.

Quote from: Shyam Hembram on February 17, 2013, 06:13:53 PM
RCB7X RADIO have flap system but i dint find any individual switches for it.It works only  as programable mixes with other  controls. It also has  a 3 way toggle switch,so can i use that switch individually for flap control,or can i modify that switch 

If the manual I see is correct, the "FLAP SYSTEM" in "INPUT SELECT" menu can be assigned to a 2 or 3 position switch, or a rocker switch or inhibited.  No need to mess with any programmable mixes. 

Have you gone through the manual ?

I have found it in the rocker switch and much thanks for your information.

Quote from: anwar on February 17, 2013, 06:19:16 PM
Before that, why were you looking for more channels ?  Flaps seem to have nothing to do with additional channels.

Since you did not respond to this question, I guess this was just a mistake on your part (seeking more channels on this radio)... and you really did not need this ?