No, you are not allowed to book a EU domain if you don't live in Europe. Only exception to the rule is having an administrative contact with an European address of your own office in a European nation regardless the country you actually live in
If i buy a P.O number in any EU country, then is it possible to register domain? because i know a premium domain and i want to register that domain & then sell for profit. I don't have any plan to develop that domain. Thanks
You can register a .EU though any domain registar which can use their own EU entity to be a registrant contact. You can do this but make sure that your ownership over the domain will be guaranteed from the domain name company... which is legally impossible ... but you can still use it.
You may check at Eurodns, it seems they have a good promo code for 50% .eu discount according to this list of eurodns voucher codes.