Every Regional Center has its own requirements.
Before the I-526 is filed, the EB-5 personal investment funds have to be transferred, usually, to the Escrow account of the EB-5 Regional Center project. The EB-5 Attorney will assist in the preparation of the I-526 supporting documents, including showing lawful source if investment funds.
Before filing the I-526 petition, the investment capital needs to be deposited into the project escrow account. Because each Regional Center has different rules and regulations, the best way to be sure is to work with your EB-5 attorney about these matters.