Can i send SMS through Ipad Air Space Grey using cellular network?

Only if you also has an iPhone.

Without an iPhone your iPad cannot send/receive SMS.

An iPad is not a phone. It uses the cellular network only for internet data. The iPad cannot natively send SMS or MMS text messages, nor can it make phone calls. If you have an iPhone the iPad can use the Continuity feature to send text messages through your iphone. But the iPad cannot send text messages alone.