0612 is not a country code. Numbers inside a country start like this: Zaporozhye, Zaporizhzhia (Ukraine), Orange (Moldova), Patna, Bihar (India), Telia (Lithuania) and others. The first digit 0 is the trunk prefix for domestic calls and is dropped from abroad.
Have the full number? Check it in the number lookup.
| Area or operator | From abroad | Inside the country |
|---|---|---|
 Zaporozhye, Zaporizhzhia · Ukraine | +380 612 … | 0612 … |
 Orange · Moldova | +373 612 … | 0612 … |
 Patna, Bihar · India | +91 612 … | 0612 … |
 Telia · Lithuania | +370 612 … | 0612 … |
 Kramfors · Sweden | +46 612 … | 0612 … |
If a number starts with +, the first 1–3 digits are the country code. If it starts with 0 (8 in Russia and Kazakhstan), it is a domestic number: an area or operator code follows, and from abroad the 0 or 8 is replaced with + and the country code. The same digits can mean different places, so where the call came from matters.