iPad No Sim Card

Apparently you're not alone is this matter, a Google search revealed that this is most likely a faulty iPad. You will probably have to take it to an Apple store to have it looked at. Have you tried a different SIM card?

Thanks THX 1138 for your reply. I'd tried with several SIM cards and also from different service provider too, it still showed "No Sim".

Don't know if it will work but try a reset. Hold down the sleep button and the home button for about 10 seconds until you see the Apple logo, then let it boot.