ETH and BTC are the two main crypto currencies I would say in general but to buy PTR now would be done on an exchange. Im not sure I know of any open exchanges now or even planned which are listing PTR, Im sure there must be something in the works but Ive not spotted that stated on the thread.
It should be in the OP if there are any, since there is the sanction question there has been a lack of news generally. I would expect to hear far more of PTR considering its size under normal circumstances
Blockchain technology
The Petro will be based on the NEM (New Economy Movement) platform. See the White Paper for more details. And read more about NEM:
https://nem.io/Supply
A total of one hundred million (100,000,000) Petro will be issued. The Venezuelan State will not be able to make new emissions of Petro.
82,400,000 tokens will be offered to the market in two stages, a pre-sale and a public ICO. They will be distributed according to the following list:
44.0% will be available for the initial public offering of the cryptoasset.
38.4% will be available for private sale
17.6% will be retained by the Venezuelan Superintendency of Currency and Related Activities (SUPCACVEN)
Quoted from the OP, Im not a fan when the OP fails to be updated with new info as anything can get lost in discussion back and forth and of course many commentating here have no interest in actively trading so would not know these details.
Ive scanned their various media accounts but I see no recent information
The ICO is still open. People can still buy Petros from the official website (only with BTC, ETH, XEM and Rubles - no Dollars and Euros are accepted).
There are no other particular updates at the moment. The white paper says the ICO will be open until all coins reserved for it will have been sold (about 80 million PTR in total). They haven't sold all of them, very hard task with all the limitations they have.