Tour rented accommodation - there's three of them (8)
I believe the answer is:
triplets
'them' is the definition.
I can't judge whether this definition defines the answer.
'tour rented accommodation there's three' is the wordplay.
'tour' becomes 'trip' (I've seen this in another clue).
'rented accommodation' becomes 'let' (a property which is let out).
'there's three' becomes 's' (I am not sure about this - if you are sure you should believe this answer much more).
'trip'+'let'+'s'='TRIPLETS'
'of' is the link.
Can you help me to learn more?
(Other definitions for triplets that I've seen before include "Splitter (anag)" , "three children to come together" , "Three born at the same time" .)