Setting, about phone, there shows your baseband
And in status shows your IMEI, provide us the necessary information.
Also you can go general section and found XXEMG4 modem to flash it, might pretty much solve your problem
Sent from my GT-I9300 using xda premium
if my words are useful or helpful to you , i will appreciate it you click thanks button
Nexus S GT-I9023 (died due to BOOTLOADER error / 12 months) ---> Galaxy Nexus GT-I9250 (accidentally and sadly lost / 2 months) ---> Galaxy S III GT-I9300 (be robbed, thanks to the Fuc.king Spanish Public Order !!! 2 months ) ---> Galaxy Ace GT-S5830 ---> Galaxy S III GT-I9300 (second one , hope won't get robbed again !!!)