One of the following suggestions may help you:
Your server is currently offline.
GameTracker needs your server to be online before you can add it to our database. Please restart your server and make sure it's up before hitting ADD SERVER again.
You entered the wrong query port.
Please update your query port and hit scan again
Your server is firewalled.
Please turn off any firewall you have that may block scanning or whitelist the gametracker scanning IP addresses:
208.167.241.190
208.167.241.185
208.167.241.186
208.167.241.183
208.167.241.189
108.61.78.147
108.61.78.148
108.61.78.149
108.61.78.150
Your server isn't configured to respond to scan requests. To configure your server to respond properly to GameTracker.com scan requests, please visit the forum thread here http://www.gametracker.com/games/minecraft/forum.php?thread=58741

my server is online anytime but gametracker say ur server is off line what should i do?

What have you tried, per the messages?

i wanna help how to add myminecr.. server here

How to Claim my Server????
I dont understand!!!