The jungle cat is a small wild cat species (“somewhat larger and lankier than domestic cats”) living over a large distribution from the Middle East to the Far East. Over this large area it coexists with other carnivores of a similar size. There is not much information on what eats jungle cats. However, I’ll quote verbatim what the Sunquists say in their seminal work Wild Cats of the World (2002) (highly recommended):
“Jungle cats may also be killed by larger predators, and the rarity of jungle cats in some parks in Sri Lanka is thought to be due to predation by leopards.”
There it is: leopards eat jungle cats. Wild cat species do prey on one another. For example caracals prey on African wild cats. It is about relative size. The leopard is much larger than the jungle cat. The leopard is around 7 times heavier.