Merhaba - Turkey. We also use Alo when we answer the phone :)

Nyob Zoo (Nyawh jhoong) --> Hmong

Xin chào - Vietnamese
こんにちは - Japanese (good afternoon) pronounced "kon ni chi wa"
你好 - Mandarin pronounced "ni hao"

Salut (French)

Guten Tag / Hallo -> German
Dobar dan -> Croatian/Serbian

Hai (Indonesia)
你好 / ni hao (Chinese)

你好 (pronounced as ni hao) Chinese! :)

Choni - kurdish
Merhaba - arabic
Hallo - Dutch
Hola - Spanish

Namaskar - In Oriya & Hindi

also be it can be 'Namastey' in modern Hindi day to day speech
Namaskar is the old usage type. I guess.

"Kumusta!" -- Tagalog (Filipino language). Also means "how are you?" if you add a "ka" afterwards.

"Cześć!" -- Polish.

Hai [Malay]

Hola! (Spanish)

Alo (Haitian Creole), however it's mostly use for talking on the phone.

Bonjou (good morning) Bón Aprè Midi (good afternoon), Bon Swa (good afternoon but for after 5 going to six o'clock).

We don't really use Hello, but the translation to English would he Alo (again, use mostly when talking on the phone). The ones above is what we use ad greeting (going with the tome of the day you encounter said person).

Nyob zoo (hmong)