Might tired kangaroo be thus restricted? (3,2,6)
I believe the answer is:
out of bounds
'restricted?' is the definition.
(thesaurus)
I cannot understand how the rest of the clue works.
(Other definitions for out of bounds that I've seen before include "Skipper so exhausted" , "lying beyond field of play?" , "taboo" , "like an exhausted kangaroo?" , "Off limits" .)