The establishment of hatto was in China, not India, and it is believed that it had already been established in the period of the Northern and Southern Dynasties (China), when Buddhism began to spread through the noble class.
法堂の成立はインドではなく、中国であり、仏教が貴族階級に浸透し始めた南北朝時代(中国)には既に成立していたものと思われる。