Where is the number 5 cylinder on a 2002 Jaguar S Type 3.0I am having a misfire in the number 5 cylinder and how are they number located?

You should look in the Manual, as V6 engines don't have a common Pattern. But in general the uneven numbered cylinders are on the passenger side of the car so it should be (if standing in front of the car) the sternmost cylinder on the left.

There is as well an other Solution that Mechanics would do, but that requires a bit of experience. You could start your engine and let it run on idle. Then you remove the ignition plugs one by one (put the previous one back in before removing the next as you want only one being removed at a time). Now you hear for the sound of your engine, if it changes, this cylinder was going well and if it stays the same you found the cylinder that is going bad. (Be careful as unburned fuel will shoot out of the Hole where the ignition plug was sitting!! Its not that dangerous as the petrol is nearly nonflammable under atmospheric pressure, but you obviously should not bring open fire near it anyway)

This is a common trick but depending on what causes the misfire it could prove useless in this case.

I hope this helps!