To find the fuel pump relay, you'll need to consult your Grand Vitara's owner's manual or a repair manual specific to your year and model. These manuals will show you the location of the relay box (often under the hood or in the passenger compartment) and identify the fuel pump relay, usually by a diagram or label.
Sometimes, the fuel pump relay is also indirectly controlled by other safety systems (e.g., the crankshaft position sensor) which need to be functioning properly before power is sent to the relay. If you are troubleshooting a fuel pump issue, checking the fuses and other related components is also important.