One of two or, perhaps, three I brought in (6)
I believe the answer is:
either
'one of two' is the definition.
(I've seen this in another clue)
'perhaps three i brought in' is the wordplay.
'perhaps' indicates an anagram.
'brought in' is an insertion indicator.
'three' with letters rearranged gives 'ether'.
'ether' placed around 'i' is 'EITHER'.
'or' is the link.
(Other definitions for either that I've seen before include "could be one of two" , "Word introducing first alternative" , "Her tie (anag.)" , "One of two alternatives" , "Each of two; moreover" .)