You can also use the plural forms: "Bem-vindos" (for multiple males) or "Bem-vindas" (for multiple females).
For a mixed group, you can use the gender-neutral form: "Bem-vindos".
Here are some other ways to say "welcome" in Brazilian Portuguese:
* Seja bem-vindo/a: This is a more formal way to say welcome.
* É um prazer recebê-lo/a: This means "It's a pleasure to receive you."
* Sinta-se à vontade: This means "Make yourself at home."
* Aproveite: This means "Enjoy yourself."
The best way to choose the right phrase depends on the context and the level of formality you want to convey.