someone said today its network barred and not blocked
can it still be done Dr?
If it has been blocked by the network, usually for unpaid contract or reported lost/missing/stolen then no it can't be done, well, it can, but only by changing the IMEI number which is illegal and could get you five years free hotel accomodation.
Unlocking just removes the sim locks so you can use other networks in it, perfectly okay to do.
Are you sure it has been blocked ?