in this link there are companies that are accredited to register domain http://www.internic.net/origin.html -- does cheapname, godaddy, ... are among this list -- is it better we directly register by one of them (relaibality, speed, access, services...) -- does countery is important to select one of them?
Here is the ICAAN Accredited list: http://www.icann.org/registrars/accredited-list.html As for your questions, I am having a little trouble understanding them fully.
also in one of these site I read 665$ prepay and 6.9$ per year I just thout I need to pay 6.9$ per year what is it the prepay actually how much it cost to register a domain name?
There is no fixe price for domains, some offer them for as little as $1.99 whilst others will charge $10 for the same domain. Namecheap, godaddy and 1and1 are the cheapest.