This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
The exact historical development of 箼 is uncertain. It combines 竹 (bamboo) with 屋 (roof/house), but the original meaning and component relationship are unclear.
The top is bamboo 竹 and the bottom is a house 屋. Picture a bamboo house, but its meaning remains unclear.
For オク, imagine an oak tree growing beside a bamboo house: oak -> オク, and the bamboo house stands nearby.