The main pathways
Family-based green cards run from "immediate relative" categories for spouses, parents and minor children of US citizens, which have no annual quota, down to preference categories for siblings and adult children, which have long queues. Employment-based cards run from EB-1 for extraordinary ability and multinational managers, through EB-2 and EB-3 for degree-holders and skilled workers, usually requiring an employer to complete a labor certification (PERM) first. The Diversity Visa lottery covers a limited set of countries; Pakistan has generally been eligible while India has not, and rules change year to year.