Garment displayed by royal in attempts (6)
I believe the answer is:
shorts
'garment' is the definition.
(shorts is a kind of garment)
'royal in attempts' is the wordplay.
'royal' becomes 'r' (abbreviation).
'in' means one lot of letters goes inside another.
'attempts' becomes 'shots' (shot is a kind of attempt).
'r' placed within 'shots' is 'SHORTS'.
'displayed by' is the link.
(Other definitions for shorts that I've seen before include "Boxers" , "Item of clothing; drinks of spirit" , "Reduced trousers" , "bottom gear" , "Trousers that end at or above the knee" .)