The Tocharian B word ṣkas
Word ṣkas
ʂ k ɐ s
IPA ʂkɐs
Meaning six

Comments
Douglas Q. Adams, “Etymological Dictionary of Tocharian B”, 1999, Brill

Other words that might be of interest
ṣe ‘one’, wi ‘two’, trey ‘three’, śtwer ‘four’, piś ‘five’, okt ‘eight’, okt-yaltse ‘eight thousand’, oktante ‘eighth’, oktamka ‘eighty’, piṅkte ‘fifth’, śtarte ‘fourth’, ñu ‘nine’, ñultse ‘nine thousand’, ñumka ‘ninety’, ñunte ‘ninth’, ṣukt ‘seven’, śak-ṣukt ‘seventeen’, ṣuktante ‘seventh’, ṣuktaṅka ‘seventy’, śa(k)-ṣkäs ‘sixteen’, ṣkaste ‘sixth’, ṣkaska ‘sixty’, trite ‘third’, täryāka ‘thirty’, trai ‘three’