Hi, no i'm afraid not sorry, Tinfoils quickly grow into monster fish with sizes of around 13" being the norm,
Small fish would quickly be consumed even by relatively small Tinfoils
Welcome to the forum Amanda.
It would not be a good idea to mix them now. In the long run a tinfoil barb can grow to about 14 inches, 35cm, long. At that size, a neon would not even be noticed on the way down.