Insurance editorial to help you answer, more questions can be answered online.
The prerequisite for retirement is that you have paid all your contributions for at least 15 years, and then it's a matter of where you receive your benefits:
If you paid contributions in your domicile before you reached the legal retirement age, but not in a foreign country, then no matter how many years you have paid in a foreign country, you will have to transfer back to your domicile, and then apply for retirement in the place where you are domiciled.
If before reaching the legal retirement age you were not contributing in the place of domicile, but in a city outside the country, and you have paid contributions for at least 10 years in that city, then you have to transfer the pension insurance you paid in the other cities to that city, and then go through the retirement procedures in that city.
If before reaching the legal retirement age you are not in the place of domicile to pay contributions, but in a city outside the country, but you pay contributions in the city less than 10 years, then you have to transfer to the last city where you have paid contributions for 10 years, and then go through the retirement procedures; if you pay in a foreign country, are less than 10 years, then they are all transferred back to the place of domicile, and then in the place of domicile to go through the retirement procedures.
Now, pension insurance can be transferred to the whole country.