If you check out the fast tract diet, the author uses glycemic index of carbs to differentiate those that are more easily digested versus those that end up feeding your gut bacteria. It basically turns the mainstream advice that you should prefer low GI complex carbs on its head.
Jasmine rice is much more easily digested than basmati rice and this is due to the ratio of amylopectin to amylose. Amylopectin digests much faster and more completely. These differences are reflected in their respective GI values.