A black ring? All female IRNs have a faint ring ariund their neck that is just lighter than their color. Males' rings are very distinctive and by now he would have the black ring.
2 Budgies, 3 Cockatiels, 6 GCC'S, 2 Crimson Bellie Conures, 9 Sun Conures, 2 Major Mitchells, 12 Eclectus parrots of various ages, 2 BF Amazons, 2 Hahn's Macaw's, 1 Red Tail Black Too
So he/she would have hatched around Aug 2011 so that would make your bird approx 8 months old. Sorry to have to tell you this but you will have to wait until your bird has it's second molt at 2 years, then if it a male you should notice little pink feathers at the back of the neck start to appear & the black will start to get heavier. By the time the 3rd molt at 3 years if it's a male would be fully colored.
The only way for you to know sooner is to have a DNA test done.