That is incorrect. The law covers all land and requires a minimum calibre of 9,2 mm and 5,3 kJ for elephant,buffalo and hippo. 7mm & 4,3 kJ for lion and 7mm & 3 kJ for leopard.
There are threads on the forum debating whether 9,3 x62 makes the energy but basically 9,3 x 64 and upwards is legal...