Leo’s righteous humor aside, you need to do more of the legwork here. We’re volunteering our time; please be respectful of it. You could have easily Googled how to clear the ITL from a Cisco phone, for example.
If you’re not comfortable with the basics then I suggest opening a TAC case and having them walk you through it.
Since you deleted and re-added the phone, it’s worth verifying that the cluster and database replication are healthy. There are CLI commands for both of these tests.
After that you really need logs (CCM SDL and phone console) and potentially a PCAP. Logs will tell you what each side (phone & CUCM sub) believe caused the phone not to register. The PCAP would be necessary if they claim the TCP connection was lost - which would point at some other network connectivity issue.
