No Service GSM Mode 2/3/4G Card….AT&T lock

Hi, Please help, I lock the AT & T operator and not the sim card LTE Vodafone Czech Republic. He still says NO SERVICE. Please help buy here R-SIM 10plus is only installation, and then I buy Gevey ios9 and it is not at all .. Iphone 6 ios 9,2,1 thanks :confused::(:confused::(