For me it was a little mysteriuos. As I said, I've bought OpenBTS Development Kit. With hardware I've also received couple China Mobile SIM cards. One of SIM cards IMSI was :
  So I've configured OpenBTS like this:
GSM.MCC: 460
GSM.NCC: 3  (David suggested me change this parameter, but in later testings I've changed this to 0 - all phones has successfully registered).
I've also changed Band and ARFCN. But I think the problem disappeared after restarting USRP.... And maybe attaching second antenna to RF1 (dlink).  And also works only couple  my mobile phones. Others I think are locked.
 I've also some questions...
1) Is there any docummentation about OpenBTS CLI? Is't possible reload config and to see all registered IMSI in CLI?
2) I've configured Control.OpenRegistration: 0 . As I understand IMSI list would be in asterisk sip.conf?