With the covid-19 pandemic Argentina decided to establish limits for the return of its citizens and some of them could return to the country 5 months after this decision, and they had to remain for that time in foreign countries. As far as I know many countries let you stay in their borders for 6 months if you arent a citizen. What can happen if a country decides not to allow return to a large amount of citizens like this, which measures can be taken against citizens in the foreign country with a decision like this? Would they acquire a status of refugee or something or would they be considered criminals?
A question like that is impossible to answer in general, but your question includes some incorrect assumptions.
- Many countries try to prevent visitors to become de-facto residents through repeated visits. For instance, the Schengen area limits visitors on short-stay visa to 90 days out of every 180-day rolling window, and the UK seems to give their immigration officials more discretion on every re-entry.
- Many countries give political asylum to people who are persecuted in their home country. A pandemic, or generally bad living conditions, do not count as persecution.
- Many countries give refugee status to people who have to flee war or disaster in their home country. The default case for these rules is a person who is in danger and wants to travel to a safe country.
- Then there are rules for force majeure when a person in the country is forced to overstay through no fault of their own. How that is handled usually depends on how cooperative the visitor was at securing a timely return or a visa extension. During the early days of the pandemic, there have been blanket extensions in some countries. As travel re-opened, these have run out.
One of the differences between the last three bullet points is how long the stay is permitted. Political asylum tends to be for the long term, refugee status lasts until the end of the disaster, and a force majeure exception might just last a few days.
So if this is not just a hypothetical question, contact a lawyer or the immigration authorities where you are now. Generic answers on Stackexchange cannot replace specific, professional advice.