Complex sentence: The Koiri (or Koery) are a Hindu Kshatriya caste, whose traditional occupation was as cultivators believed that they are descendent of Shri Kusha (twin son of Lord Rama another being Lava) so form a part of wider Kushwaha community.
Split into simpler sentences: The Koiri (or Koery) are a Hindu Kshatriya caste, whose traditional occupation was as cultivators. Koery believe that they are descendent of Shri Kusha (twin son of Lord Rama another being Lava) so form a part of wider Kushwaha community.