An Etymological Dictionary of the German Language/Annotated/Roche
Roche (1.), masculine, ‘ray, thornback,’ from Low German ruche; compare the equivalent Dutch roch, rog, Anglo-Saxon reohha, *rohha, whence Middle English reihe, rouhe; also English roach, rocke? (English ray is derived from Latin raja, whence also Italian raja, French raie).
Roche (2.), masculine, ‘castle’ (at chess), from the equivalent Middle High German roch, neuter; borrowed with chess-playing from the French (roc, whence also Middle English and English rook). The ultimate source is Persian rukh, rokh, ‘archer mounted on an elephant’ (at chess), Derivative rochieren.