Chief Botha Sigcau, 65, president of the Republic of Transkei since it became the first black homeland to gain independence from South Africa two years ago, died of a heart attack Friday in the capital city of Umtata.

His death was announced here by Nggondi L. Masimini, who represents Transkei unofficially as minister at large for the Western Hemisphere. Since it became independent, Transkei has failed to gain recognition from any nation other than South Africa, and relations with that nation were broken a year ago.

Mr. Sigcau, who also was a member of Transkei's Parliament, was paramount chief of the Pondo tribe. He was regarded by many as a "father figure," Masimini said.

Working with Paramount Chief Kaiser Mantanzima, who has been prime minister of Transkei since independence, he was considered a leader in efforts to establish a true national identity for Transkeians of all tribes.

The Republic of Transkei, with a population of about 3.5 million, is in Southeast Africa on the India Ocean. It was the first of nine tribal areas to become independent in a South African plan to consign 19 million blacks to tribal states. The plan has been condemned as extending South Africa's apartheid policy.

Stella Sigcau, daughter of Mr. Sigcau, was the country's first minister of finance. He also is survived by his wife and two sons.