Hi! As you already know my phone was blocked by my government as the phone doesn't have FCC certification recognized by this country! After talking with the company who sold the phone to me I decided to Root the phone to change the IMEI. I'm writing because my phone now finally has a new IMEI but after changing it my phone doesn't have signal! Woth the message no registered on the network. Im Wondering if you can help meto fix this issue? I think it has to do with the baseband

As stated many times in this forum, rooting can't be officially supported for obivous reasons.
The only thing i can do is keeping your thread open so that other users can help you with this "issue"