Hi!
I think ritu you should use the 9-bit mechanisum specified in the books like 8051 by Scott makenzie.
This mechanisum works in a way that master send address of addressed MCU with (for e.g) bit9 = 1. The addressed MCU than Listens to the Master. while non addressed MCU ignores data.
On software side this should look as,

mov A,#01 ;address of slave.
call enableslave ;make this slave 1 active.
.
. ;do normal communication.
.

Here you must note that this mechanisum is for 1 master and all other slaves.i.e. 1 stem and all other leaves.
If you want that 1 is super master which communicates with masters (which are working as slaves for super-master) and masters communicate with slaves.i.e. I big stem consisting other small stems and small stems are connected with leaves. Then masters must have 2 serial port of some thing like that.
I think is will help great if you tell us what exactly you want to make.

Thankyou!