@Mahim007 

Hello, we would like to know more details which will help us analyze the issue you are experiencing.

For the auto-reboot issue:
1. When did you purchase it, does the reboot issue occur when you first installed it or is it happening after some special activity, such as high loading or streaming? Have you ever upgraded the router firmware or changed some setting on it when this issue begins to happen?
2. How often does the reboot issue occur? If possible, try to reduce the connected devices, modify the Transmit Power on the router to middle or low, go to Wireless > Wireless Advanced, then change the Transmit Power to "Middle" or "Low", then monitor again.
3. Additionally, check this FAQ to confirm more details: https://www.tp-link.com/support/faq/3032/.

For the wireless range issue, check this article:

https://www.tp-link.com/support/faq/2291/