Tseku (Tzuku) is a

Tibetic language The Tibetic languages form a well-defined group of languages descended from Old Tibetan (7th to 9th centuries).Tournadre, Nicolas. 2014. "The Tibetic languages and their classification." In ''Trans-Himalayan linguistics, historical and descriptiv ...

of Tibet. Tournadre (2013) classifies it with

Khams Tibetan Khams Tibetan () is the Tibetic languages, Tibetic language used by the majority of the people in Kham. Khams is one of the three branches of the traditional classification of Tibetic languages (the other two being Amdo Tibetan and Ü-Tsang). In ...

References

Languages of China Central Bodish languages {{st-lang-stub