You must first obtain a case number (which can take about a month). The amount of time required to obtain the IGA recommendations depends on each particular IGA. After the IGA recommendations are received, the State Department then reviews the case (four-five months). The State Department then forwards its recommendation to the appropriate USCIS Center. Different USCIS centers have different review processing times.
You should request your program sponsor to extend your program to the maximum program duration. If you are about to reach the maximum duration period, you should consider an F-1 program and obtain USCIS Form I-20, Certificate of Eligibility for Nonimmigrant Student Status. In the alternative, if an employer is willing to sponsor you for an O-1 visa, you may apply for an O-1 visa.