Your passport should be valid for a minimum period of 6 months from the date of entry.
On arrival in the country, you’ll normally be allowed to remain in Ecuador for up to 90 days per year. If you’re planning to stay for longer, you should apply for a visa up to 180 days, which is possible in Ecuador before the 90 days expires.
If you enter Ecuador via the border with Peru or Colombia you must insist on being given an entry stamp at the border showing the date of your arrival.
Also check with your embassy of origin to be sure what you’ll need.