I-130 has been approved this june, how long dose it usually take to get interview for visa? i am in Nepal?

that would depend entirely on which immigrant category your petition falls under. Immediate relative petitions, spouses and minor children of US citizens are valid immediately, but take 3-6 months to process and schedule from the time they are approved. If you're the spouse of a legal permanent resident or fall into some other family preference category, you could be waiting for years before the petition is valid for use.