https://www.britannica.com/biography/Suryavarman-II
There are tamil inscriptions in Angor Wat and the architecture is highly influenced by Chola/Pandya architecture.
https://www.quora.com/How-did-Tamil-Kingdoms-influence-Angko...
Some examples of what the Cholas and Pandyas accomplished which stands to today are
Tanjore Temple (Cholas) https://www.youtube.com/watch?v=XX9-__GWHnA (Edit: Unfortunately, this video also has a lot of old western cliched ideas of Hinduism, hope I had a better documentary to share...) (for scale, this can fit 200 Taj Mahals)
Madurai Meenakshi (Pandyas) https://www.youtube.com/watch?v=iQjI3DPt9Tk
You can see that the architectural pattern of 4 directional gateways with a central temple complex is basically the same as Angor Wat.