blocked SIM is pretty much a SIM card that has no access to providers cell network. the data on SIM card is still there so if you found your lost and inactivated/blocked SIM card, yes.. data is still there behind your original PIN code.
If sim is still lost somewhere out there, it's lost, you have no way to recover data from it.
If you have messages saved on the lost sim card, then no, you cannot. If you had backed up your phone, and stored the messages on the phone itself, or on a cloud drive, there is a good chance you would be able to get them back.
blocked SIM is pretty much a SIM card that has no access to providers cell network. the data on SIM card is still there so if you found your lost and inactivated/blocked SIM card, yes.. data is still there behind your original PIN code.
If sim is still lost somewhere out there, it's lost, you have no way to recover data from it.
So has it been lost, or is it blocked?? If it is blocked, your provider can help you un-block it. If it is lost, as little_me and I have said, you have no hope of recovering anything from that SIM.