Here is a rough guide to estimate your chances at Stanford + Ivy caliber schools in the US:
- SATs above the 75th percentile for that school’s admitted class (typically above 2300 total)
- Good english speaking and writing skills (as evidenced by TOEFL or study at international english medium school)
- Class rank which places in the top 5% of your school
- Meaningful extracurricular activities which show a passion or skill that the college desires (artist, mathematician, future politician, etc).
- Have several accomplishments that show international level recognition, and must be validated by an external source.The recognition should preferably be from a widely recognized body. Examples include: nobel peace prize, international olympiad, Intel ISEF, participating on your country’s olympic team for a sport, etc. You really have to have something jaw-dropping that would leave most people amazed (winning a few international spelling bees won’t cut it).
Now most top international students who apply are able to demonstrate #1 - #4 easily. Its only those students who are able to show #5 have a decent shot of being admitted. Since the financial aid pool is quite limited only a handful of schools are need blind for internationals.
Having said all of this, with your SAT scores, I really think it will be unlikely you will improve your scores from a 1500 range to over 2300 within a year’s time. This is almost impossible. The odds are stacked against you. If I were you, I would focus my efforts on attending a college in your home country, do as well as possible, and then look towards doing a master’s degree in the US.