Nehru The Making of India By M. J. Akbar 609 pages. Viking. $24.95.

The reactions of people who met Jawaharlal Nehru on his first visit to the United States as Prime Minister of India in 1949 indicate how complex was the interweaving of the public and private lives of one of the great figures of the 20th century. For Adlai E. Stevenson, Nehru was one of the tiny handful of historic figures who have influenced ''the implacable forces of our time'' and a member of the even smaller company who ''wore a halo in their own times.'' A less reverential comment came from a reporter who noted that Nehru had left behind him ''clouds of misty-eyed women.''

Secretary of State Dean Acheson thought Nehru was so important to India's survival and ''so important to all of us, that if he did not exist - as Voltaire said of God - he would have to be invented.'' Then he added his final judgment: ''One of the most difficult men with whom I have ever had to deal.''

M. J. Akbar, one of India's ablest journalists, has provided a brilliant portrait of this mercurial, sensitive, powerful figure while giving a skillful analysis of the historical forces that led to the transformation of Britain's Indian empire into the modern states of India and Pakistan. On one level, Mr. Akbar shows why Nehru was so important as a political leader in this process of imperial decay; on another, he provides new insight into Nehru's personal development through his relationship with the two figures that dominate his life, his father, Motilal Nehru, and his political guru, Mohandas K. Gandhi.

But Mr. Akbar's work moves on a third level of meaning, which he makes fairly explicit in his preface as he explains why there was room for another Nehru biography. Mr. Akbar needed to discover, in his telling phrase, ''why the unity of India had been destroyed in the name of Islam.'' It is this discovery that gives special depth to his understanding of Nehru and his place in history. Historians may question both of Mr. Akbar's underlying premises - that there was an Indian unity in the sense that he uses the term and that it was destroyed by Islam - but his exploration of Nehru's life through these premises has produced a fascinating and rewarding work.

Jawaharlal Nehru was born in 1889 in Allahabad. His father was a very successful lawyer who lived in luxurious style in a splendid mansion, enjoying the company of the highest-ranking British officials as well as of the Indian elite. An early expression of his ambition for his son was shown in sending him to Harrow to prepare for entrance to Cambridge. The choice of Harrow was symbolic: it was the school for the rich and aristocratic upper classes who ruled England, and Motilal was envisaging his son in some sense a ruler of India.

''Stumbling Towards Destiny'' is the evocative title Mr. Akbar gives the chapter in which he describes the beginning of Nehru's commitment to the new style of politics that Gandhi had introduced into India. Mr. Akbar outlines the drama of the struggle for the allegiance of Nehru that went on between Gandhi, the ascetic with strange ideas about food, clothing, sex and the renunciation of violence, even in a good cause, and Motilal, the lover of all the good things that money can buy. The struggle was resolved by Nehru's becoming, in effect, a son to both, but as Mr. Akbar makes clear, his attitude toward the world and its pleasures remained that of Motilal, while he accepted Gandhi's politics of nonviolence as a technique to fight the Government.

The figure who dominates much of Mr. Akbar's book, even more in some ways than Gandhi or Motilal, is Mohammad Ali Jinnah, the founder of Pakistan. The book is an exploration of how India was divided by Islam, and Jinnah is for Mr. Akbar, as he was for Nehru, at the center of this vivisection. It is fair to say that in his analysis of the political developments of the period from 1922 to 1947, Mr. Akbar accepts Nehru's interpretation of these crucial years without much criticism. This means an emphasis, as conventional as it is unproven, on the argument that the British rulers of India deliberately created ill will between the Hindus and Muslims throughout the 20th century and in the end worked with Jinnah to divide India.

Mr. Akbar shows more of an awareness than Nehru always did of the role of Hindu chauvinism, with its strident insistence that India was a Hindu country and that the Muslims and other minorities were living there on the sufferance and good will of the majority. He gives little attention to what Jinnah insisted was a primary cause for the growth of Muslim separatism, namely, the Hindu religious vocabulary in which Gandhi defined the Indian nationalist ideology.

After Nehru became Prime Minister in 1947, his concerns for the nation he had led to freedom were manifold: preserving national unity, all the more precious because of partition; giving a measure of justice to India's poor; maintaining democracy, and, a cause at the core of his being, helping India find her rightful place in the family of nations. Mr. Akbar interweaves all these concerns into his narrative as, indeed, they were interwoven in Nehru's life.

Nehru had power in a measure that no other ruler of India had ever possessed, and under him India made enormous progress, but at his death great poverty remained, as did antagonism between religious groups within India and hostility between India and her neighbors, Pakistan and China. When the poet Tagore had read Nehru's ''Autobiography,'' he told him that the details of his life were a tangle of facts but that they led finally to a person who is ''greater than his deeds.'' Mr. Akbar uses that phrase for the title of his concluding chapter, and it is a fitting summary of an extraordinary life of disappointment, loneliness and achievement.

photo of Jawaharlal Nehru