Sometimes, yes, they can be used interchangeably. But not always.
Because a Toss is a type of Throw. For example, in BJJ or Judo you can do a Hip Toss which is a kind of hip throw.
But I might ask you to Toss a coin, but I won't ask you to Throw the coin. If I say Toss the coin, most people will assume I mean catch it also. If I say throw the coin, most people will ask: where to?
Toss also has a naughty meaning, so some people avoid this word, except in certain contexts. To call someone a tosser, is a big insult.