I don't know it can be solved purely by Ohms law or not.
But a trick is assuming I flow in at one end, it divide into 3 current evenly, then each further divide into 2 currents, then converge back into 3 currents to flow out.
So I*X=1/3IR +1/6IR+1/3+IR
So the resistance is 5/6R.
If you don't depend upon symettry, can you directly
solve this problem?