Gamble on it, backed in place of many mounts (5)
I believe the answer is:
tibet
'place of many mounts' is the definition.
'tibet' can be an answer for 'place' (I have seen 'High place' mean 'tibet' so perhaps 'place' could also mean 'tibet'). I am not certain of the 'of many mounts' bit.
'gamble on it backed' is the wordplay.
'gamble' becomes 'bet' (bet is a kind of gamble).
'on' means one lot of letters go next to another.
'backed' says the letters should be written backwards.
'it' backwards is 'ti'.
'bet' after 'ti' is 'TIBET'.
'in' acts as a link.
Can you help me to learn more?
(Other definitions for tibet that I've seen before include "Himalayan country" , "woollen fabric" , "Part of Asia" , "Region of SW China" , "region out East" .)