It is difficult for both for Swiss abroad and resident Swiss to get a grant in Switzerland if they want to study abroad.
First of all, you should enquire about possible grants in your parents' country of residence. Above all, this concerns dual citizens and swiss citizens living in a country of the European Union (embassies in the relevant country can give further information).
In most cantons, studies abroad are not eligible for grants. When you can prove that you cannot do the education or training you want to do in Switzerland will a few cantons consider a grant.
This grant programme is mainly aimed at Swiss university students or post-graduates (in some cases, also artists) who want to study abroad.