Wheres the proof for how proles are being kept busy by the Inner Party so they don't think and revolt?

To find proof of how the proles are kept busy, let's take a look at their lifestyle. Notice, first of all, how the Party lets them live in their own districts, free from intervention and free from the telescreen. By doing this, the Party gives them a sense of freedom.
Secondly, there are no prohibited activities in the prole district. They have pubs where they can drink alcohol, they can gamble, they are not subject to food rationing, and they can marry whomever they choose. This ensures that the proles are happy—so happy and content with their lives that they have no reason to revolt. Why would they change their lives when they have everything they could ever want and need?
Of course, we know that this control over their lives is an illusion because control is really in the hands of the Party. However, by giving the illusion of control and by never meddling in prole affairs, the Party ensures that they will never think about revolting.