Need Advice.

I’m a Bangladeshi. I have done my O’Levels. Can I skip A’Levels and go for other courses like GED or SAT to get admission in a US college? If so, Should I take GED or SAT? Which one would help me more in increasing my chances to get into a US university?

Are your parents wealthy and have a quarter million dollars to pay for yur undergraduate studies?
If yes, then apply to the universities that accept O’Levels.
If not, then you must take 4-6 AS Levels and do well, then select 3 (4) A-Levels and do well, as well as prepare for the SAT or ACT plus SAT Subject tests. Your only chance at a scholarship is if you have A-Levels.
There’s a middle ground with some “automatic scholarship” universities such as Temple and UAlabama, but your parents would need to have about 15,000 dollars per year for your education, and you need to check and see if the policies have not been changed (ie., if O’Levels are still acceptable.)

Forget GED. It’s an exam for those who don’t finish high school. It’s useless for purposes of university admissions for an international student.