The US Visa in My Passport Says: "Visa - R" and "Type/Class - b1/b2". How Long Am I Allowed to Stay in US on Business For?

When you arrive in the U.S., immigration officials will indicate on your I-94 card how long you can stay in the U.S. Be sure not to stay beyond the date indicated. Typically, B1/B2 visa holders can stay up to 6 months.