By HENRY RAYMONT

Cuban veterans of the unsuccessful operation against the regime of Premier Fidel Castro in April, 1961 issued a call to exile organizations yesterday to join in a new armed effort to invade Cuba.

During a noisy, crowded rally at the Manhattan Center, members of the veterans' organization, which calls itself the 2506th Cuban Assault Brigade, proclaimed a Central Liberation Front. It will seek to coordinate political, insurrectional and military strategy against they Cuban Government.

Many leaders of the new front were supporters of Fulgencio Batista, the former dictator, and speakers at the rally took more time to denounce moderates among Cuban exiles who were unwilling to lend their support than to attack Mr. Castro.

Waldo Carmona, general secretary of the new organization, envisioned "a great expeditionary force" that he said would be preceded by "a concerted plan of attacks to soften the Cuban regime before a new invasion."

Addressing more than 2,000 Cubans in the meting hall at 311 West 34th Street, Mr. Carmona said the movement was "open to all, from Fulgencio Batista - to Juanita Castro."

Miss Castro, a sister of the Cuban Premier, who broke with his regime, was among those who refused to join the new movement. Others included Manuel Urrutia Leo and Carlos Prio Socarras, former presidents, and Aureliano Sanchez Arango, a former Minister of Education. Their names were vigorously booed by the crowd.

The biggest ovations went to references to General Batiste and to Rolando Mansferrer, a former Senator and close friend of the former President. Mr. Mansferrer sat on the stage with uniformed members of the brigade and other supporters.

Those attitudes reflect the deep differences and rivalries among those who continue to regard the ouster of the Communist regime in Cuba as their main goal. Manolo Ray, the left-of-center exile leader who was a member of the Cuban National Revolutionary Council that organized the 1961 expedition, was not even mentioned as having been invited to help organize the new front.

Listed among its supporters were Carlos Marquez Sterling, a farmer Premier; Guillermo Bell, a former Foreign Minister and Ambassador to the United Nations; Manuel Antonio de Varona, a rightist exile deader; Eusebio Mujal, a former trade union leader, and Guillermo Martinez Marquez, a newspaper columnist and former president of the Inter American Press Association.

The group has elected as president Alberto Martinez Echenique, head of the veterans association. Jose Perez Sanroman, brigade commander, was named chief of the military preparedness committee.

Speakers took varying attitudes towards the United States. Mr. Carmona deplored "the inexplicable indifference" of Washington towards Cuba, but Mr. Bell praised President Johnson, especially for his policies in Vietnam and the Dominican Republic.

There were cheers for Joaquin Balaguer, a conservative who has been elected President of the Dominican Republic. His liberal opponent, Juan Bosch, was denounced by several speakers as "a Castro agent."