I believe it's a jenday, but as already stated he is too young to tell. Did the person that you got him from not know? Was this his breeder? God I hope not, that's a bad sign! And he looks very young, possibly younger than 3 months based on his feathers. Is he eating solid food regularly without any issues?
Just to point something else out to you, it looks like you've got another sun or jenday conure in that small cage that your new baby is crawling on... You're not keeping them in the same cage, are you? If you are you need to separate them immediately, as even if they seem to be getting along alright now you never know when suddenly the first, older bird becomes territorial and attacks the new bird. Also, if that is the cage you're housing them in it looks much too small for one Jenday/Sun Conure, let alone two.
You should have any new bird that you get quarantined from any birds you already have for at least the first 30 days he's in your home to protect your other bird or birds from illness and disease, as it's quite common for baby birds to have bacterial and/or fungal infections. Your new baby should be kept in his own cage in a completely different room from your other birds and they should have absolutely no contact for at least 30 days, as birds instinctively hide any signs of illness, so you have no idea whether your new baby has any current infections that he can spread to your other birds. 30 days is typically enough time for illness to appear in your new baby. I don't know how long you've had him but you should also take any new bird you bring into your home to a certified avian vet in the first couple of weeks you have him, just for a wellness checkup. It not only helps catch any illnesses he may have, but it protects you if God forbid your new baby does become ill and dies in the first month or two that you have him, which is not uncommon. I don't know where you got him (I can't imagine that his breeder wouldn't be able to tell you what species your bird was, lol) but if it was a private party sale he could have come from a bird mill, that's very common, and they often carry diseases/infections.
"Dance like nobody's watching..."
Does your conure get along OK with your tiel? I have 2 tiels and have wanted to get a GCC for a REALLY long time... in the very distant future I would love to get one.
