The Suzuki Gixxer can be a suitable motorcycle for riders of shorter stature, including individuals who are 5 feet 3 inches tall. However, it's important to keep in mind that personal comfort and reach can vary depending on factors such as leg length and riding posture preferences.
The Gixxer has a seat height of approximately 795 mm (31.3 inches), which is considered moderate for a standard/naked sport bike. While this height may require you to stretch a bit to plant both feet on the ground, many riders of your height have successfully ridden the Gixxer comfortably.
To get a better sense of how well the Gixxer suits you, it's highly recommended to visit a Suzuki dealership and request a test ride. By sitting on the bike and trying it out firsthand, you can assess how well your feet reach the ground and whether the riding position feels comfortable for you. Additionally, adjusting the suspension settings or using a lower-profile seat cushion or lowering kit can potentially improve the reach to the ground for shorter riders.
Remember, finding the right motorcycle fit is subjective, and what works for one person may not work for another. It's crucial to prioritize your safety and comfort while riding, so take the time to test different bikes and models to determine which one best suits your specific needs.