Hi Dheeraj,
Please refer to the 5.2.2 Forming or Joining a Distributed Network Zigbee 3.0 Light Bulb Documentation JN-AN-1218.
Using the Control Bridge as the coordinator, I recommended to set up the Permit Join for a few time.

The documentation mentions: in this case Dimmable Light Router:
• On a light device (from this Application Note) that is already part of this network, press the RST/RESET button 3 times at one-second intervals, or press DIO8/GPIO4 once.
This will cause a Management Permit Join Request to be broadcast to the network to open the Permit Join status for a period of 180 seconds.


And the end device could be the JN-AN-1219.
5.2.3 Joining a Network
The switch device is an End Device and, as such, must join an existing ZigBee network. The network join process is as follows:
1. Start Network Steering on the switch by pressing any button on the DR1199 Generic Expansion Board. As soon as a button-press is detected, the device will search for a suitable network to join. The LED pair LED1+LED3 and LED2 will flash alternately during this state.