Yes. As per the Notification No. 43/2017 dated 29/11/2017 of Central Tax, if the registered person purchased raw cotton from an agriculturist, purview of rule u/s 9(3)of CGST act eill be applicable.
Yes, Buying cotton (kapas) HSN 5201 by registered person from farmers (unregistered persons) is liable for RCM as per Notification 43/2017 CT (r) dt. 14/11/2017