reverse charge on gst

If the person(reipient) is registered under GST then he has to pay GST @ 18% under rcm.But if unregistered then no obligation to pay gst under rcm as sec 9(4) is applicable only on supply by unregd person to regd person.

IF a registered person (recipent) take industrial property on rent from a registered person (supplier)

then who will have to pay GST on it.

recipent under RCM (under rent expenses) or

supplied have to pay GST (under rent income)

or both.

and if supplier pays GST on rent income, can he get it back??