Will I get PR or Green Card after Completing my Studies in USA? video explains that there is no direct program available in USA that grants Permanent Residency or Green card after completing studies from USA.
To get the green card to USA, you have to find the employer first in related field of studies. Once you have employer/Job , then employer is going to file for your H1B Visa ( Work Visa). Once you have the work visa in USA, you can ask the employer to apply for Green card. If employer want you then the company will apply for your green card. The processing time for the green card depends on the country in which you born. Each county have Quota for Green card per year. For some of the countries such as India and China, the waiting list is long and it can take them 12-15 years to get green card.
