@Sreekrip 

Hi

If the extender cannot be configured successfully, it is recommended that you refer to the following three methods to reconfigure it:
1. Via the Tether APP. The Tether APP could be obtained from APP Store or Google Play Store. In the Tether APP, click the "+" button at the upper right corner, select "Range Extender" and the Tether APP will guide you through the setup process. This is a step-by-step FAQ which contains more details: How to configure Range Extender via Tether APP.

2. Via a web browser, the Range Extender has a web management interface available. Please connect your PC/phone to the Range Extender's default Wi-Fi "TP-Link_Extender_XXXX", open the browser and access http://tplinkrepeater.net or http://192.168.0.254, follow the quick setup procedures to setup your Range Extedner.

This FAQ provides detailed instruction through web interface: How to configure my range extender via web GUI.

3. Via the WPS button, there is a physical WPS button on the Range Extender, if your Router supports WPS as well, you may simply press the WPS button on the Router and the Range Extender in turn, the Range Extender will connect to the Router automatically within 2 minutes. For details instructions, please refer to How to configure my Range Extender via WPS button.

If the above methods still cannot help you, please provide the configuration method and the error message on the APP or Web.