How to solve Not registered on network on Galaxy S3 GT I9300

PLEASE REMEMBER TO ROOT UR MOBILE FIRST
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Download Modem files from here:

1.Modem_XXDME4:
http://www.mediafire.com/download/8s0uo5u6ana7tsw/modem_XXDME4__.zip


2.Modem DDEMG2:
http://www.mediafire.com/download/ycguvdn94169jj3/Modem+DDEMG2.zip

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soundtrack details :
Artist: Grafit
Track: Flying
Download: http://goo.gl/hg5Zl
Licence: http://goo.gl/ZSoZf