The official site is: http://www.elpetro.gob.ve/index-en.html
It is hosted in Venezuela on a government domain gob.ve.

This is a scam: el-petro-coin.com
It is hosted in Germany, no other information. They require no registration (unlike the official site) and just want you to transfer ETH into a wallet they generate and control!
You will lose everything you hive them. But the site looks very professional and beautiful, and is in the same style as the government's site. I think it will not be taken down, because the people that control the internet don't want El Petro (PTR) to succeed.

The site at getpetrocoin.com might or might not be a legitimate alternate coin, that changed its name to Locha. Not related (but opposed) to the government coin initiative.