Can I add more channels in IN865 Band?

Hello,
I am from India and I am using LoRa gateway with raspberrypi as the host. I am configured the three default channels in IN865 Band but I am getting collisions in my packets coming from two different nodes. To resolve this one method is to increase the number of the channels. I have increased the channels but I guess the device is not using these new channels. What am I doing wrong here?

How did you add the channels? Were the channels added to the backend so nodes get these channels when OTAA joining? Or do the nodes use ABP and have you added code in the nodes to add the channels?

I made changes in both the node RAK811 and packet forwarder. In node I added the channels in ch_list command. In the packet forwarder I enabled the remaining channels in the global_config.json file. I am using otaa method of joining.

OTAA changes the channel list to the channels known to the back-end when joining. If you want to add channels you will need to propose a channel plan, have it accepted by TTN and have it implemented in the back-end code.