Applicability of gst on rent charged in bill of supply

Dear Professionals,

A regsitered person supplying exempted goods to customers hence he issuing Bill of Supply for the same but he is charging godown rent charge in same bill of Supply for sale of exempted goods.

Now my question is whether godown rent will be taxable as per Bill of Supply or will it be treated as exempted supply as principal goods is exempted.

Regards 

NITIN JATAV