Formal:
* வணக்கம் (Vanakkam): This is the most common and respectful greeting, used for everyone. It can mean "hello" or "welcome."
* நல்வரவு (Nalvaravu): This is a more formal way to say "welcome." It is used when welcoming someone to a place or event.
Informal:
* வாங்க (Vaanga): This means "come in" or "welcome." It is used for friends and family.
Other options:
* சொல்லுங்க (Sollunga): This means "tell me" or "welcome to share." It is used when someone is arriving to talk or discuss something.
Note: Tamil has a complex system of honorifics and politeness, so the appropriate way to say "welcome" will depend on the specific situation and your relationship with the person you are greeting.