Good luck finding seats on flights to/from SJU right now, and for the next week or so. And, even if you get a reservation, that flight can get canceled at any time. Flights that are not military/relief flights are very limited at this time. If you are not flying to SJU as part of a relief team, you shouldn't be flying there right now. And if you do, expect to get stuck there for a week or longer. If you are trying to get relatives out of Puerto Rico, the situation at the SJU airport is quite chaotic.