how to open a closed robi sim

Solution
The only way to make a SIM work is to contact the service provider/carrier that the SIM is from and have them activate it (which will require an account with them) or, if the SIM is damaged in some way, get them to send you a replacement one.

If you are wanting to use the phone with a different service provider/carrier, then you would have to contact them and get a SIM and account with them.
The only way to make a SIM work is to contact the service provider/carrier that the SIM is from and have them activate it (which will require an account with them) or, if the SIM is damaged in some way, get them to send you a replacement one.

If you are wanting to use the phone with a different service provider/carrier, then you would have to contact them and get a SIM and account with them.
 
Solution