Reagan in the royal seat? (6)
I believe the answer is:
throne
'royal seat?' is the definition.
(I've seen this in another clue)
'reagan in the' is the wordplay.
'reagan' becomes 'ron' (I've seen this in another clue).
'in' is an insertion indicator.
'ron' inserted within 'the' is 'THRONE'.
(Other definitions for throne that I've seen before include "Ceremonial seat" , "Seat of a ruler" , "Ceremonial chair for bishop or king" , "Sovereign's chair" , "Seat of royalty" .)