Hello Alan,
Now, my radutmp is created and rawho is working. Two things needed to changes at least in my environment.
1) access point was not sending the Accounting packets properly, network guys has fixed this for me.
2. I changed nas = other in client.conf file instead of cisco (this worked)
Since all working, I have one small issue regarding radwho output.
test1 test1 shell S325 Tue 11:13 192.168.1.252
test2 test2 shell >999 Wed 10:38 192.168.1.160
00376df47b 00376df47b95 shell >999 Wed 13:39 192.168.1.245
70188bccdb 70188bccdb53 shell >999 Wed 13:40 192.168.1.245
00376df47b 00376df47b95 shell >999 Wed 13:59 192.168.1.241
test3 test3 shell S138 Thu 03:30 192.168.1.161
those test1 ---test3 actual users but other numbers are actually the macaddress of the actual client which should be the username like test4 and test5, It will be nice to know what causes that