Complex sentence: Then he moved to Haridwar and spent several years to study ancient Indian scriptures at Gurukul Kangari where he read another rare book of Aurobindo Ghosh- "Yogik Sadhan" which was translated from Bangla into Hindi by Ram Prasad'Bismil'.
Split into simpler sentences: Then he moved to Haridwar and spent several years studying ancient Indian scriptures at Gurukul Kangari. This included a rare book of Aurobindo Ghosh- "Yogik Sadhan", was translated from Bangla into Hindi by Ram Prasad'Bismil'.