What is the proper adjective for Tibetan?

Answer 1

The adjective form of Buddhism is Buddhist, using the -ist ending. As an example, "Buddhist teachings began in ancient India and quickly spread across its Asian neighbors." Teachings are the noun, and Buddhist is the adjective in that sentence. More rarely, "Buddhistic" is used.
The proper adjective for the noun Buddhism is Buddhist (for example, Buddhistphilosophy).

The word Buddhist is also a proper noun, a word for a follower of Buddhism.

Answer 2

Tibetan is the proper adjective for Tibet.

Answer 3

The word Tibet is a proper noun, the name of a specific country. The proper adjective form is Tibetan.

Answer 4

Tibetan itself is an adjective to describe things (people, culture, dance for example) that reside in or from or are related to the region of Tibet.