Hi,
Here are some suggestions for you first:
--Please ensure you have latest firmware version on this router:
https://www.tp-link.com/support/download/archer-c6/v2/
If it is not, please refer to this link to upgrade:
https://www.tp-link.com/faq-2139.html (wired connection is required)
If you are dropping on wireless only, please login to the interface of your router, change the channel to 1, 6, 10, channel width to 20MHz on 2.4G, and change the channel to 36, 44, 48, channel width to 20MHz on 5G.
https://www.tp-link.com/faq-1523.html (advanced--wireless--wireless settings)
By the way, do you have this issue on all of your wireless devices or just one of them? Can you still detect the wireless signal on your wireless devices when wireless drops?
Good day!