There's no single answer without knowing the transmission type.
To find the plug, you'll need to:
1. Identify your transmission: Check your vehicle's documentation, or look for markings on the transmission casing itself.
2. Consult a repair manual: A repair manual specific to your Jeep's year and transmission will show you a diagram with the drain plug clearly marked. This is the most reliable method.
3. Look underneath the vehicle: Once you have an idea of the general area, carefully look under the vehicle. The drain plug is usually located on the bottom of the transmission case; it's often a magnetic bolt.
Caution: Working under a vehicle can be dangerous. Use jack stands, not just a jack, and always use caution when working on your vehicle.