THis means your MCU is transmitting /comm at 9600 Baud rate.
Please do following
(1)Connect MODEM to PC serial port
(2) Using different baud rate setting try to get OK response from MODEM
(3) ONCe you get OK response set Modem baud rate to 9600 using AT command(you may have to see AT command list for that)
(4)Change baud rate of serial port of PC to 9600 and check if you are getting OK in response to AT. Is yes then your modem is set at 9600 baud and ready to comm with MCU.
(5) Check AT commnad response with MCU