Tiletamine is used less frequently than K in general and I think it's only ever supplied as a mixture of tiletamine and zolazepam in veterinary usage. It's probably rarer than you think. Nowadays it's more likely to have any number of the RC dissociatives (MXE and friends) sold as ketamine. But of course there is also plenty of real K out there too.
The only way you can say for sure is by testing your material: generally you should get it GCMS tested if possible, otherwise you will need to use your best chemical sleuthing (solubility tests, melting point, various color-changing spot tests, TLC, et cetera) to say with certainty.