Highest crit resist chance i could found was from Hogma Warrior inside Earth Tower, which is a value of 195. The Light Cap for current patch considers that.
And as for future content, if you want to consider the questioanble, just do a thing that you think that will work for the future.
Note: Lvl 3 Zalciai + 233 SPR = 0 crit resist even on Hogma Warriors. Anything above sets it down to negative.