In some of the server when I check the users logged in through the "uptime" command it shows me more number of users logged in whereas when I use the "who" and "w" command it reports me much less numbers actually logged in.

Can anyone advise why this difference is there and how I can find a remedy for this.

The server is a RHEL 3 update 6.

post the outputs of both

root:hosta# uptime
12:31:59 up 20 days, 2:58, 1474 users, load average: 0.27, 0.20, 0.18


root:hosta# w
12:32:04 up 20 days, 2:58, 1474 users, load average: 0.25, 0.20, 0.18
USER TTY FROM LOGIN@ IDLE JCPU PCPU WHAT
tpzadmin pts/0 xxxxxx.aaaaaaa Sun 4pm 1:44 15.12s 15.12s -bash
tpzadmin pts/2 xxxxxxxx.aaaaaaa Sun 4pm 6:46 13.25s 13.25s -bash
vga611 ttyp1 hostax.xxxxxxxx 12:31pm 4.00s 0.65s 0.63s bash
tpzadmin pts/3 yyyyyyy.xxxxxxx Sun 5pm 3:53 16.49s 16.49s -bash
tpzadmin pts/1 yyyyyy.xxxxxxxxx Sun 7pm 13:23 9.05s 9.05s -bash
vga611 pts/4 yyyyyy.xxxxxxxxxx 12:31pm 4.00s 0.32s 0.01s pbrun bash
root:hosta#

? they both say 1474

and `uptime` by design doesn't show you who's logged in, just the total number.

who shows the number of the users as well as the user statistics who are already logged in..in the output it reports only 6 users logged in , where as in the actual stat it is stating 1474 users.

That's a good qn ... you might find this page http://linux.die.net/man/5/utmp (and the whole site) useful.
I suspect that 1474 is actually the num of processes running, not unique user count.

I still could not understand this difference. Could you please advise?

Well, what I mean (as opposed to the manual) is that eg you could login 5 times, simultaneously, which would give you a (login) process total of 5, but only 1 unique user.
You clould also start 5 processes in the background from each login session, which would give you 30 (5 + 25) processes, but still 1 unique user logged in.
Also be aware that process count includes all the kernel processes and any other processes the system thinks it needs, see /etc/init.d .
HTH