Yes, they are able to walk backwards.
Rhinoceroses are large, herbivorous mammals identified by their characteristic horned snouts. The word "rhinoceros" comes from the Greek "rhino" (nose) and "ceros" (horn).
The largest rhino species is the white rhino, according to the San Diego Zoo. It grows to 12 to 13 feet (3.7 to 4 meters) long and up to 6 feet (1.8 m) from hoof to shoulder. It weighs around 5,000 lbs. (2,300 kilograms).
The smallest rhino species is the Sumatran rhino. It grows to 8 to 10 feet (2.5 to 3 m) long and up to 4.8 feet (1.5 m) from hoof to shoulder. The Sumatran rhino weighs around 1,765 lbs. (800 kg).
The vast majority of animals are capable of walking backwards, even if it's not a frequent occurrence. This ability helps animals get out of tight corners and helps protect them in situations when they feel threatened. Because of the usefulness and importance of this skill, it shouldn't be surprising that the number of animals that cannot walk backwards can be counted on one hand.
Here are the animals that cannot walk backwards from Animals.mom.me.