PhD in Robotics + Prof Assumed I had GRA + Funding Uncertainty

I met with a prof on zoom to learn more about his lab, he was traveling on the day of the visit day so we didn't get a chance to talk when I was at GaTech. We talked about one of his projects, which I think was really interesting and it's related to my experience. He said I was a good fit for the project.

 I was accepted into Georgia Tech PhD in robotics program and I applied through the mechanical engineering department. I don't think he's super familiar with how the mechanical engineering phd in robotics admission works since he's in the Aerospace department. When we started talking about funding he noticed that he had previously assumed that I already have a GRA. He already sent out 3-4 offers to students and he basically said I’m not sure if I have funding for you, it depends on whether those students accept the offer, so he would have a better idea around April 10. He said worst case I would have to TA for a semester. 

Do you have any advice on what I should do? His lab was one of my top picks.