Ready-made red carpet I supply, brilliant for inside (13)
I believe the answer is:
prefabricated
'ready-made' is the definition.
(similar in meaning)
'red carpet i supply brilliant for inside' is the wordplay.
'supply' indicates anagramming the letters (in a supple way).
'brilliant' becomes 'fab'.
'for inside' means one lot of letters goes inside another.
'red'+'carpet'+'i'='redcarpeti'
'redcarpeti' anagrammed gives 'prericated'.
'prericated' going around 'fab' is 'PREFABRICATED'.
(Other definitions for prefabricated that I've seen before include "Made for easy assembly" , "ready to be joined together" , "Easily erected on a building site" , "Manufactured so as to allow easy assembly on site" , "Ready to be assembled on site" .)