I want to reduce the current ripple to less than 15%. can I achieve this with say an inductor of 500uH? I am having an input voltage of 84V and I want an output of 12V 1A. Is using a large inductor a viable solution?
Some internet rando here, hard to say from the datasheet. If this was a peak current mode chip with a clock, then yes a larger inductor will reduce current ripple. This isnt that it is a hysteretic voltage mode chip with some ill defined procedure that reduces the amount of hysteresis at light load.
So buy it and try it as the best option, maybe you can simulate it, but you are left wondering about the accuracy of the models.
Alternatively examine your belief that you need 15% ripple. Did your staff numerologist suggest that? You can always add a little filter on the input of the converter or on the output of the converter to improve EMI.