President Reagan said yesterday that he will nominate Norman Braman, a Florida businessman and son of immigrants from Eastern Europe, as commissioner of immigration and naturalization.

If confirmed by the Senate, Braman, 49, would succeed Doris Meissner, named by the administration as acting commissioner of the problem-plagued agency.

Braman, a wealthy Miami Beach businessman, heads an automobile sales and leasing organization in Florida that includes the nation's largest Cadillac retail dealership.

Justice Department officials have described Braman as a manager and an organizer who can "really take hold of something and make it work." In 1964, Braman organized Philadelphia Pharmaceuticals and Cosmetics and was its president and chief executive officer. Earlier, he had founded Keystone Stores, a chain of self-service department stores in Philadelphia.

"I'm committed to a major reorganization . . . , " Braman said. "The INS is not efficient . . . . It has no data processing. It has no way of determining who's coming in, how long they're staying or when they're leaving. It goes all the way down to the district offices . . . . "

Braman was an active fund-raiser in Reagan's campaign and is close to Sen. Paula Hawkins (R-Fla.), who sponsored him for the INS post.

Reagan also said he will nominate Alan M. Hardy as ambassador to Equatorial Guinea and Howard Kent Walker as ambassador to Togo.

Hardy has been country officer for Mozambique and Namibia since 1979, and Walker deputy chief of mission in South Africa since 1979.