I have 2 clusters (4500C & 4500B) running the below versions.
4500C ver : 188.8.131.52.0
4500B ver : 184.108.40.206.0
can i restore the policy backup of 4500C on 4500B?
When you say "policy backup" this implies "policy only" when you're performing the restore (no configuration).
Also, because the 4500C is running an older version, it's just fine to restore on the 4500B running a newer version.