please help my s3- problem with network topic

i installed 4.3 Uruguay, but I lost the network tells me emergency calls only

Knowing I installed modem xxemg4 but still problem .I tried ddemg2 Again still problem

What is the solution؟؟؟:(:(:(

note: the imei Not affected and not changed

please help me

My English is rather weak I hope that I have brought the idea :(