UNITED NATIONS, N.Y., June 16 — Secretary General Thant appealed to the world community today for assistance to East Pakistan. He declared that improved conditions in East Pakistan would help to halt the flow of refugees crossing the border into India.

Mr. Thant made a separate appeal last month to governments for assistance to the refugees in India, now estimated to total more than six million.

In a related development, the International Rescue Committee disclosed it is sending a group to India with the aim of finding and assisting educators, writers, physicians and other professionals who have fled from East Pakistan.

Charles Sternberg, executive director of the Rescue Committee, who has been conferring here with United Nations authorities, explained that the intention is to assist professionals and intellectuals with emergency funds but not resettlement. The committee recognizes that as a private group it could not possibly attempt an aid program for the entire refugee population and so decided to concentrate on the professional groups, he said.