CALCUTTA, India, June 11.-American officials here are growing concerned about their planned airlift of East Pakistani refugees to camps in India's extreme northeast.

The officials are worried that if the American planes carry more refugees into the northeast, the airlift will be met with hostile and perhaps violent demonstrations. The airlift plan calls for four C-130 transports to move about 50,000 refugees from Tripura, which borders East Pakistan on the East, to the state of Assam, which borders it on the northeast.

A report in this morning's issue of The Hindustan Standard-the best informed newspaper here on refugee developments- said that 6,000 refugees had already left the northeast border state of Meghalaya and had returned to East Pakistan out of disgust, fear, grief and a feeling of uncertainty. More refugees were said to be making the return trek daily because of the hostility of the local tribal population.

The local resentment stems from the strains the refugees have placed on the poverty-level economy of the backward and hilly northeast region. The refugees have disrupted the sanitation system and have caused food scarcities that have driven prices up. They have brought cholera with them.

Two days ago, the Tribal Youth Welfare Association-a student group in Shillong, capital of Meghalaya-brought the city to a virtual standstill by calling a general strike to protest the influx of refugees and their unrestricted movement outside their camps.

Meghalaya is an autonomous state within Assam. The growing friction in Assam between the inhabitants and the refugees is reported to be nearly as bad as that in Meghalaya.

ATTEMPT TO EASE SITUATION

Tripura, a region of 4,000 square miles with a population of 1.5 million, has already absorbed more than 700,000 refugees. It is the least accessible of Indian border states, which have received more than five million Bengali refugees fleeing the Pakistani Army. Since March 25 Pakistan has been trying to crush the Bengali independence movement in East Pakistan.

The airlift was planned to ease the situation in Tripura by transferring some of the refugees there to areas that are easier to reach with relief supplies. It is expected to take about a month or so. The Soviet Union is reported to have promised a similar airlift, but no Russian planes have yet arrived.

The original enthusiasm for the Bengali independence movement and sympathy for the refugees has all but disappeared, particularly in the border states. The sentiment in the areas where the refugees are living is often close to anger-over cholera, the taking over of the schools as refugee camps, over many irritations. The first of the American planes arrived this week and flew a trial run between Agartala, capital of Tripura, and Gauhati the capital of Assam, to see of the airlift was feasible.

After the flight over hilly territory where the weather is often bad, Commander Col. Charles E. Turnipseed, said he was optimistic but the final decisions on the airlift would have to await the report of the Air Force technicians who went on the trial run.