Who owns the logo of a company after the company declares bankruptcy? For example who owns the logo for toys R'us after they declare bankrupt?
Whoever buys it.
When a company declares bankruptcy then its assets are owned by its creditors, as compensation for the standing debts.
Since usually there are multiple creditors, what happens is that its assets are sold/auctioned, as money is easier to divide between the different creditors1.
A logo or a trademark is an asset like any other and can be sold separately.
If nobody did come forward for the logo, then one of the creditors could accept it as part of its repayment.
1 If a company is in bankruptcy it means that its assets cannot cover all of its debts, so creditors are usually paid only a part of their debts.