Hi, i'm playing on Xbox now and i'm not exactly overpowered with magicka, is it possible to make enchantments on one ring that removes magicka cost from a magic school?

Cant do it with just ring but you can make 4 peices of 25%+ reduction to a school. Least two schools if you have double enchant Perk, but yes you can get to cast spells for 0 magicka as long as you have the base amount to cast them.

Actually yes, it's very possible, but you may or may not like the methods to get it. From what I've seen alot of posters here are against such "game-breaking" glitches as they believe it ruins the gameplay experience. Personally, I feel like it's a game, it should be as fun as you want to make it, you have enough silly things like restrictions and constraints in real life. If you've never heard of the fortify restoration loop, essentially you can create a fortify restoration potion (using salt piles and abecean longfins or a couple other ingredients), take any fortify alchemy gear you have (circlets, Muiri's ring, etc) off, take the potion and then put the gear back on to create another one and so on. Eventually you'll see that the boosts to your alchemy skill are rising exponentially, and at this time you'll want to create a few Fortify Enchanting potions (blue butterfly wing and snowberries). After that, disenchant some gear with the magicka effect you want (i.e. destruction costs 20% less to cast, illusion costs 20% less to cast, etc), take the Fortify Enchanting potion and add the enchantment to your item of choice. If you went high enough with the fortify restoration loop you can have gear that allows you to cast destruction spells at 98,510% or such less cost, which equates to not taking any magicka to cast it. I've got an entire set of such gear on my "goofaround" save and it's pretty awesome to use endless telekinesis and such. I'd just advise against going too high as sometimes you can glitch it into negative values. Hope this helped!