I need to order a new pulley it doesn’t spin smoothly what the name of this pulley I’m a little confused.

 

it's the supercharger belt idler pulley.
please confirm on yours with the pictures on the following site:
https://www.autoreservejaguar.com/xj...er-pulley.html

 

@ 98Jagxjr: You did not write, in which country you are...
The link above gives you a price of 32 Pounds....
I strongly recommend two things:
1. Remove the pulley, of which the bearing if probably buggered. If it is a metal idler pulley, you will most likely be able to swap the bearing (assuming you have an hydraulic press). If not, take your idler pulley and go into any automotive accessory shop - They will most likely have a generic pulley (which is the same) for about 1/4 if the price above.
2. When you have removed the drive belt anyway (to remove the idler), check, if all the other pullers are well & sound. The is a chance, that you will find another idler puller with the same issue...