Installing BESClient & a running service will not guarantee it will be showing in BigFix console.
You need to validate -
A. You are able to telnet to its parent relay over 52311 (or whatever custom port you have for BigFix infra).
B. 52311 TCP/UDP bi-directional & ICMP echo reply communication allowed in between your client machine & BigFix Relays.
C. BESClient log should be showing below two statements.
i. Relay Selected
ii. Report posted successfully