I really love the name [name]Tai[/name] … short for Taichi. If I were to use [name]Tai[/name] in the future, I wouldn’t just be able to use it as is (unless it was a middle name), and I wouldn’t be able to use Taichi because as much as I love it I can’t take it too seriously. Is there any other name that [name]Tai[/name] could be a nickname for?
I like [name]Tai[/name], but I’m with you, it’s not very long and Taichi is a type of martial arts… It’s pronounced like Tie right…the same as [name]TY[/name] in [name]Tyler[/name] and other names? If that’s the case, I think any of the [name]TY[/name] names could give you the nn you’re looking for.
Aktaion – [name]One[/name] living in Attica (old Greek name)
Aristaios – most useful (Greek)
Clotaire – glorious strength
Etai – strong
Nantai – chief (Native American)
Taiga – big and gracious
Taiki – big tree (this is so close to Taichi)
Taima – born during a storm
Taiwan – island
Taizo – third born son
Voltaire
Macintyre – the son of the carpenter
Styles – steep ascent
Tycho – hitting the mark (Greek)
Tyjah – one who is intelligent
[name]Tyler[/name]
[name]Typhoon[/name]
[name]Tyrone[/name]
[name]Tyrell[/name]
[name]Tyson[/name]
Tyvon – naturalist
Tywyn – sea shore
[name]Tiberius[/name]
Tico
[name]Tide[/name]
[name]Tiger[/name]
[name]Titus[/name]
Those are all the names I can think of that could get the nn [name]Tai[/name]/[name]Ty[/name]. [name]Do[/name] you like
Yes, it’s pronounced like [name]TY[/name] 
I’m starting to love Tyjah now … can I use [name]Tai[/name] as a nickname for that one though? I feel like all the names I like on your list, I can only use [name]Ty[/name] instead of [name]Tai[/name].
Well, [name]Ty[/name] and [name]Tai[/name] are said the exact same way so I don’t see the problem. Hardly anyone ever sees the nickname written out, so it’s just the sound people are going to be familiar with so any of the [name]TY[/name] names can have the nickname [name]Tai[/name] because it sounds exactly the same as [name]Ty[/name].
Also, if you love [name]Tai[/name], and really don’t want a full name, just go for it. It’s like [name]Kai[/name], which so many people use on it’s own, so you shouldn’t feel like you have to have a full name. [name]Just[/name] my 2 cents 
I like [name]Ty[/name] as a stand alone. I know it’s unisex but I’d guess [name]Tai[/name] was a girl because [name]Ty[/name] is mainly used for boys.
The only longer names I like are [name]Tyson[/name] and Titan