I am going to do my graduattion project in communication in one part in my project: i need an electronic circuit which can call a mobile number using sim card
A SIM card is nothing more than a flash memory card, you'll have to figure out the what every data line does, how it stores information, how it interfaces to a particular phone's uController etc - in other words you're going to need a full schematic of the phone in question and probably a lot of programming info they won't let you in on.
Can you expound on what you actually expect this to do by writing up a real scenario with examples?