It depends on the size of the project. Attached to every stage of a project, there are timelines according to which the YESAA committee, the review committee—depending on the size of the project and what levels it goes to—has to respond. Now this could include timelines regarding requests for more information, and there's also an onus on the proponent to come back with the required information.
On June 12th, 2012. See this statement in context.