What law of physics specifically?
If it is a law of physics related to Electromagnetic waves, the concept included the idea of EM waves bending around the world, which was later confirmed possible by Guglielmo Marconi, who found that EM waves don’t only travel in straight paths. The EM forces which Tesla used in his design were (re)discovered by the conventional scientific community in the 50s.
The concept of the tower was to create a circuit which would tap into the Ionosphere to conduct electricity. The Tesla coil can demonstrate that electric current can be directed through the air. The current would travel to its destination through the ionosphere (a layer of atmosphere rich in free-electrons). The return conductor would pass through the earth (or alternatively a body of water) like modern SWER AND old Telegraph/Morse code lines used. All concepts we can see demonstrated later on and/or at the time, and we all know many of Tesla’s “crazy” concepts have been stumbled back upon as possible/legitimate.
The only portion of his design that’s workings were not known/showcased to the public was the way he would direct the lightning form the tower up to the Ionosphere. As we know, he studied the effects of high-altitude in the conduction of lightning/electricity in the Colorado Springs lab. He is said to have wrestled with the concept for a while before figuring out the design, which had not been made public by the time the project was shut down (due to insufficient funding). In fact, there was an incomplete glass dome structure to be formed housing by the design. It was likely another concept we will stumble upon or have already stumbled upon that people would have thumbed their noses at at the time. We know he utilized particle beam technology in designs for a different invention, and an earlier invention utilized similar concepts of radiation and we now know that particle beams can direct lightning, so the design could easily have utilized that technology.
My post however was more asking about logistically likely locations for these 30 or so towers to be located.