select object_name(p.object_id) as tbl, 
       p.index_id,
	   au.total_pages,
	   au.used_pages,
	   au.type_desc,
	   cast((au.total_pages - au.used_pages) * 8. / 1024  as decimal(10,3)) as unused_Mb
from sys.allocation_units au
     join sys.partitions p
	    on au.container_id = p.hobt_id
where object_name(p.object_id) = 'N34_28'
order by au.total_pages - au.used_pages desc;

alter index all on FN1534_28 reorganize;