Select S.no, Number, Stage from table
where S.no in (3,5,8,12)
See what you get when you don't explain yourself?
This answer is correct as it does answer your question. Because I am nice I will interpret your intent:
with MyCTE as (
Select
S.no,
Number,
Stage,
Row_Number () OVER (
Partition By substring(Number,1,1)
Order By Stage desc) as Num
from table
)
Select no, Number, Stage
From MyCTE
Where num = 1