You have done masters from Karachi university Pakistan so how many credits hours you needed to complete masters in usa and is your degree consider bachelors here in US?

Most colleges and universities within the US, require coursework and degrees from outside the country be evaluated by an official evaluation agency within the US. Based on the evaluation agency's recommendation, the college or university will determine whether the coursework is equivalent in content and credit hours to the one's offered at the school. It is not a guarantee that just because the evaluation agency equates the coursework to US standards, that the receiving institution will accept them, but it does give them something to go on. As an example, one of the most widely used evaluation agencies on the US eastern coast, is the World Education Services (WES) located in New York City. You should contact the institution of your choice for transfer information, seeing that each college or university will have policies and procedures particular to itself.