Don
I don't think so. If they have Renault engines, their team name would be Williams Renault at the least. I doubt Jaguar would want to stick their name on it aswell, and have 2 car makers in the team name. TATA might still invest and use another brand though.
I think you mis-understand me
Jaguar as engine supplier...
Williams-Jaguar effectively. The two companies are talking, we know this as they have linked up with the road car project.