Vetoes keeping Irish children in Scotland (6)
I believe the answer is:
bairns
'children in scotland' is the definition.
(I've seen this in another clue)
'vetoes keeping irish' is the wordplay.
'vetoes' becomes 'bans' (banning is a kind of vetoing).
'keeping' indicates putting letters inside (some letters kept inside).
'irish' becomes 'IR' (abbreviation for Irish).
'bans' enclosing 'ir' is 'BAIRNS'.
(Other definitions for bairns that I've seen before include "Scottish wee ones" , "Children, in Scotland" , "Scottish children with brains" .)