All trains has specific loco link....for example Karnavati Express has specific loco link as BRC WAP-4/WAP-5...
BCT Rajdhani has specific loco link as GZB WAP-7
It has nothing to do with zone or specific loco shed or locomotive....Just one loco link...one or two types of locos of 1 or more shed is given specifically...to that train...and if another locomotive instead of that specific loco is given to that train it is considered as #offlink..!!
There...
more... are so many other zone trains which travels in WR and hauled by WR locos...for ex Ahimsa Express Swaraj Express...TVC Rajdhani.... Ranakpur Express...Jaipur Bandra....etc are other zone trains but hauled by WR Locos.