both, netstat -in and ipconfig -a show multiple entries on some machines.
One some machnes they just display one entry apart from lo0.


netstat -in
Name Mtu Net/Dest Address Ipkts Ierrs Opkts Oerrs Collis Queue
lo0 ............
hme0 ..................
hme1 ...................

How to identify,which is the current machine IP address out of hme0,hme1 etc?

But vvejendla, you can have multiple ip address depending on the network interfaces you have ? that is, you can have installed two nics on the same server either with different ip addresses, and both are the MACHINE ip addresses. In order to know the "ip address" of the machine, you would need the "interface" name you want to lookup. This is not only on unix, but on every other operating system out there. (am I right?)

SunOS and FreeBSD allow you to run ifconfig without specifying a network interface. The '-a' option can be used to check all interfaces. Of course, to modify anything an interface name is necessary. However, HP-UX requires that an interface name be provided.

As fidodido said, that depends from system to system. Some systems will have two network interface cards, some will have one. Systems that are setup as high availability clusters have even more (We have HP-UX systems with 4 NICs - one in use, one failover, two for cluster heartbeat).
Any of the IP addresses shown in netstat/ifconfig can be used to access the system as long as that IP is accessible from the rest of the network.

i have the following function in my .bashrc ( I'm running solaris)

getip ()
{
/sbin/ifconfig eri0 | awk '/inet/ { print $2 } ' | sed -e s/addr://
}

it prints just my ip