Not sure about your Id standard, but if you can extract it then you could use DENSE_RANK

E.g.

SELECT ID

FROM

(

SELECT *, DENSE_RANK( ) OVER ( ORDER BY CAST( RIGHT( ID, LEN( ID) - CHARINDEX(' ', Table1.ID ) - 1 ) as int ) DESC ) AS Rnk

FROM

(

VALUES

('1 B12'),

('2 B13'),

('3 B14'),

('4 B15'),

('5 B16'),

('6 F12'),

('7 F13'),

('8 F14'),

('9 F15'),

('10 F16')

) Table1 ( ID )

) OutputTable

WHERE OutputTable.Rnk <= 3