Archaic noun meaning 'whereabouts' or 'location'; not used in modern Japanese. The modern equivalent is 居場所 (いばしょ) or 所在 (しょざい).
In the old document, it is written, 'No one knows his whereabouts.'
Compound of 居り (おり, continuative form of 居る 'to be') + 所 (どころ 'place'). The exact historical derivation is uncertain, but it follows a common pattern for location nouns in older Japanese.