Where one may see M. Caine performing? (6)
I believe the answer is:
cinema
'where one may see' is the definition.
(place to see films)
'm caine performing?' is the wordplay.
'performing?' indicates an anagram.
'm'+'caine'='mcaine'
'mcaine' is an anagram of 'CINEMA'.
(Other definitions for cinema that I've seen before include "Iceman (anag)" , "Film industry" , "Silver screen" , "Film theatre" , "(Building showing) films" .)