Select
case when nn is null then fio else ‘Пусто’ end as Fio2,
case when nn is null then Inn else ‘Пусто’ end as Inn2
From
(
Select distinct Fio, Inn, IDRow_In_Group as NN From table
Union all
Select distinct Fio, Inn, Null as NN From table
) q
Order by fio,inn,NN nulls last
--
Получается то же самое что и в предыдущем ответе

Select
case when nn is not null then fio else ‘Пусто’ end as Fio2,
case when nn is not null then Inn else ‘Пусто’ end as Inn2
From
(
Select distinct Fio, Inn, IDRow_In_Group as NN From table
Union all
Select distinct Fio, Inn, Null as NN From table
) q
Order by fio,inn,NN nulls last
--
Получается то же самое что и в предыдущем ответе