Help! I don't catch gsm after flashing rom

I have got my GTN7100 originally with android 4.3 on SHV- E250S hardware.
As i am newcomer in phone flashing i did not save my EFS so i lost it.
Now i run 4.4.2 and the model is now GTN7105 but IMEI= null/null so no network but i have WIFI access.
Hel please!