Yes, pickles would be counted as a vegetable. A 6 oz. serving would be appropriate, or a combination of pickles and other vegetables adding up to 6 oz. total.
Watch out for sugar in bread and butter pickles. Typically, there is no sugar in dill pickles, but you should check the label to be sure.
If you eat a small quantity of pickles (less than 2 oz.) it can be counted as a condiment.