@Prashanth_42 Hello,
Please check if WiFi Leds or Signal Leds are ON on the range extender, if Leds are OFF, means RE does not connected to router sucessfully.
Here is a guide to troubleshoot RE installation step by step, kindly refer to Case2 to verfity password, reset RE and resintall it again:
Has connected to TP-Link extender but no internet, what can I do?
https://community.tp-link.com/en/home/forum/topic/198516
May I know how about the Led status on range extender after installation, what is the model of your Router, thank you.