tyflow is sold privately to individuals and is not released to a pirate site to the public out of respect for the developer. i also had a respect for the developer , but not anymore .
This website showed up in Google search https://docs.tyflow.com/ which says tyFlow is a particle simulation plugin suite for 3ds Max. It also has a free version, subject to the following three limitations:
Multi-threading is disabled
GPU acceleration is disabled
tyCache export is disabled
which makes it useless for anything other than testing/trying it out I'd guess but idk, I don't use 3ds max.