Bactrian is a dead language that was spoken in Bactria area which is the place that contemporary Afghnistan locates.
Bactrian is an East Iranian language which was in active use from 300 BC to 1000 BCE. It was the official language of then regional power Kushan Empire.
IU offers Bactrian studies course in the semester of Fall 2023. Please contact CEUS (https://ceus.indiana.edu/about/contact/index.html ) for detailed information.