Hello@786-RAHUL , when tp-link RE works in range extender mode, and it always uses the same channel as router as extender has to repeat the signal on the same channel as the router and could not be changed.Did you use RE as an Access Point before? As only use RE in Access Point mode ( wired RE to the router via Ethernet cable) the channel could be changed. https://www.tp-link.com/support/faq/1401/