The Netherlands embassy in Riga does not issue visa.
Latvia is part of the Schengen area. Do you have the nationality of Latvia? Or do you have a valid Schengen visa or a residence permit for Latvia? Then you do not need to apply for a short-stay Caribbean visa to travel to the Caribbean part of the Netherlands (Aruba, Bonaire, Curaçao, Saba, St Eustatius or St Maarten).