The TP-link repeaters do have a DHCP server that is by default set on “auto”. If it sees a DHCP server traffic it will not intervene. If it does not it will act as DHCP server.
However for me the combination of Mikrotik and a TP-link RE450 (different but similar model) was problematic with default setting or with DHCP set to OFF on the RE.
I did not test again with newer RouterOS versions, and it worked well with non-Mikrotik DHCP server but Mikrotik AP. (My home setup)
And I could make it work with the RE DHCP ON, and active with a second pool part of the same subnet.
https://www.tp-link.com/nl-be/support/faq/691/
http://forum.mikrotik.com/t/tp-link-repeater-re450-not-assigning-ip-address/118970/1