Not permanently, it's not really big enough to house 1 full grown Oscar. I would try my best to go larger, but I believe you could "cram" an Oscar into a 75 gal as long as you took good care of the water. I am not advocating "cramming" fish into small tanks though. Get something that makes the fish thrive!
yea dont get like stuck with 5 blue acaras and 2 7" pacus in a 55g like i have, and have ur parents not let you get a bigger tank so u have this very overcrowded tank with crappy water and to make matters worse in the tank has a breeding pair of blue acaras.
my pacus outgrew my tank about 4months ago and im still trying to get rid of them. i do a 50% water change every 5 days or so as needed, clean filter every week, and replace carbon and the micron pads every other week.