In Windows 2003 by default we have 2 sessions enabled.What is the procedure to increase it to 10.

Dunno if this works in windows 2000 server, but it is worth a try:

Click Start, then Run, type "gpedit.msc" (without quotes) and press ENTER;
open Computer Configuration > Administrative Templates > Windows Components > Terminal Services;
double click "Limit number of connections", choose "Enabled" and set the maximum number of concurrent connections to 10.

also
 http://www.brianmadden.com/content/article/The-Ultimate-Guide-to-Windows-2003-Terminal-Server-Licensing

yes once you go to more than 2 sessions it is no longer considered remote administration but now termianl services sessions.
and Terminal services sessions have licensing implications as indicated by MRhusy.

regards

If you want more than the 3 admin Terminal sessions (2+1 console), then tyoy have to use terminal services proper. The three sessions are provided for admin use (not a good idea to have 10 people all administaring a machine at the same time I would not have thought !)

For more info on terminal services see http://www.microsoft.com/windowsserver2003/technologies/terminalservices/default.mspx. You can enbale Terminal services and run it without sdditional licences for three months on a trial basis