If this is one of the amber seeding that were distributed by Patrick or Sheehan, I would recommend that you put it in the ground. These trees were distributed for free in the hopes of bringing a great jackfruit to the US. So far the results have been very good. My tree, unfortunately, is sickly.
I have jackfruit trees that have been putting out males for the last three years without fruiting.
Gnappi, taking 4 to 5 years to fruit is not a bad thing for a jackfruit tree. Small trees produce inferior fruit, fruiting puts a lot of strain on the tree, and BKL is a heavy producer.