We are given a right rectangular prism.
Let us have a look at each of the given options.
1st option:
Points A, B, E, F are coplaner.
This is correct since all these point lie on the same plane (the tope plane)
2nd option:
Points C, D, E, F are coplaner.
This is correct since all these point lie on the same plane (the diagonal plane)
3rd option:
AE || HD
This is correct since the side AE is parallel to the side HD.
4th option:
BC ⊥ BF
This is correct since the side BC is perpendicular to the side BF.
5th option:
CG || HG
This is false since the side CG is not parallel to the side HG but rather they perpendicular.
6th option:
ABCD is a rectangle
This is correct since since it a right rectangular prism.
Therefore, only 5th statement is false.