How can I apply for I-485 before my parents get EB-5 visas?

No, as a derivative dependent, the principal applicant must first be approved for an immigrant visa before you can adjust status.

It is problematic for you to file an I-485 application in this situation. You should apply for an immigrant visa at the appropriate U.S. consular post in India.

You can either go through consular processing with your parents in India and get an immigrant visa with them together, which is the fastest way for you to get lawful permanent resident status, or you can file an I-485 as a following-to-join derivative in the U.S. after your parents enter into the U.S. with their immigrant visas. It is impossible to file your I-485 application before they have their Immigrant Visa interview.

Your parents need to be in the U.S. and eligible to apply to adjust status for you. Alternatively, if they have entered with green cards, you can file as a following-to-join derivative.

As dependent to the primary petitioner, you are not likely to be interviewed before the primary petitioner.

If your mom or dad is the principal on the I-526 approval, she or he must process first and enter the U.S. and become a permanent resident and then you can adjust your status. It is best for you to go through the consular process with them.

Yes if you are living in the U.S. currently, but the principal must become a resident before the derivative does.

They need to get their immigrant visas and enter the U.S. first. Otherwise, you can go to the consulate with them and get your own immigrant visa.