Tigers are almost found in the whole Asia. And during ice age,the South East Asia Sea was actually terrestrial. Many animals like elephants,rhinos, monkeys and wild boars were able to migrate there.
In Borneo, leopard is the only big cat can be found until today.All I know leopards are not superior as tigers when they are in a duel.
Crocodiles of Borneo is the only animals can threaten tigers.
There are enough food source, suitable climate and tropical forest,yet tigers still can’t be found there.