The Grenade is the standard frag, modeled on the M61, and a fixture of the series for years. You cook it or lob it into a group for a strong area blast, at the cost of a short fuse you have to time. It stays useful for clearing cover and dealing with vehicles or clustered enemies.
Grenades usually come from Ammu-Nation in packs or get looted during heavier fights. GTA 6 has not spelled out its gun store stock, so buying them once available is the likely path.
The community companion for Grand Theft Auto VI. Database, maps, guides and tools for Vice City and the state of Leonida.