Not even on the stones or on the ground. Otherwise if you wish to use it in no matters purposing, you need to request for permission.
With than information to be filled and purpose of the shoot need to be known by them in advance. What if you want a wonderful sunrise but not allowed to used tripod, what’d you get?
From what I concerned is how they going to manage tourists of not being took any professionalism image to share the world neither improving tourism industry in Cambodia.
As a landscape photographer with passionate of publishing the wonderful things in Siem Reap may vary feel dissatisfied with this prohibitions.