Looks as if your Tiel has lost or damaged its tail feathers and some of the tips of its wing feathers. The common cause is an overly small cage and/or being young.
When he grows up he will have a molt and the long tail feathers will grow back. He will probably be much less clumsy then and so he won’t break off the long tail feathers.
There is nothing you can do to "fix it" it's common in young birds to not be as aware as they need to be about the tail. With age comes more awareness of the tail and more carefulness to not damage it.
It will naturally regrow during the next molt.
When my Sun Conure was young he broke most of his tail feathers.
And here he is after his first molt
You can also see that he replaced the tail and clipped wing feathers during the molt.
Here are the clipped wing feathers after he naturally molted them