Rajiv Gandhi faces daunting task; Indian leader must quell riots, counter regionalism, preserve democracy

Rajiv Gandhi, India's seventh and youngest prime minister, confronts a task as awesome as any world leader could face - how to hold together this disparate nation of some 700 million people, seven religions, and multiple languages, cultures, and castes.

Mr. Gandhi's most immediate need is to restore communal harmony between Hindus and Sikhs. Since his mother, Indira Gandhi, was assassinated by two Sikhs from her security guard Wednesday, violence against Sikhs has flared throughout the country's northern Hindi belt.

At time of writing, the rioting, shooting, bomb explosions, and killing were growing worse. It was not clear how or when the security forces would regain control.

Beyond that, he will have to contain mounting regional pressures at home; find his own balance in dealing with India's neighbors and the superpowers; and learn to master India's mighty experiment in mass democracy.

At times such as this, it sometimes might appear that this complex nation has begun to come apart at the seams. But India's multitudes, steeped in history and resilience, normally tend to be an unrevolutionary, largely fatalistic people. And they expect that the only surviving son of Mrs. Gandhi, herself the daughter of the indomitable Jawarharlal Nehru, will continue the family tradition of ruling the nation. The Nehrus, more than anyone else in the country, have always been considered ''national'' figures - ''all-Indian.''

Indian democracy is a largely feudal mix. As family businesses are inherited, so are political empires which groom political heirs.

Mrs. Gandhi was a woman of action and political instincts; but her critics charged that she lacked her father's vision and dreams. Rajiv is more like Nehru , gentler, more conciliatory. But if Rajiv Gandhi fails to gain a firm grip on power quickly, or if his hold should falter even slightly, India could pay an enormous price in uncertainty and political turmoil. For his mother left an unenviable legacy to the largely untested Rajiv.

During her 16 years as premier, Mrs. Gandhi tended to concentrate power largely in her hands; to denude the once-great Indian National Congress party of anyone deemed a threat; and to minimize the stature and importance of the Cabinet, Parliament, and the country's 22 eclectic states. Hence, her assassination was all the greater loss.

Now Rajiv Gandhi must move swiftly and adroitly to contain the anti-Sikh violence - which had reportedly taken more than 100 lives by Thursday night - before it leads possibly to an even more shattering Sikh backlash against Hindus in the Sikh-dominated Punjab. And he must do it at a time when regional tensions , once largly contained, have begun to mount again.

When Mrs. Gandhi sent the Indian Army into the Sikhs' holy Golden Temple in June to rout out militants, the repercussions were felt from Kashmir in the Himalayas to the sunbaked villages of the south. Likewise, when the elected chief minister of Andhra Pradesh State, N.T. Rama Rao, was overthrown in August, it prompted a month of sustained national protest. Eventually the central government felt compelled to reinstate him. It was a rare instance of Mrs. Gandhi's acknowledging defeat.

In both cases, the Indian Army - the only institution in the country to have transcended corruption, poltical meddling, and feudal disputes - was called upon to settle or oversee the resolution of civilian political crises.

The trend toward deploying the Army in domestic crises has spurred many retired generals to express a commonly held fear that this institution could become politicized, further crumbling a vital bulwark of the world's largest democracy.

The fact that democracy has survived in India against such heavy odds - the depth of division and tension, an annual per capita income of $230 a year, a 66 percent rate of illiteracy, and a population explosion adding 15 million Indians each year - lends weight to Mrs. Gandhi's claim that a powerful central government was indispensable in ruling India.

Now it is Rajiv's turn to confront the task of keeping the country together. There also is a consensus here that the new Prime Minister Gandhi must take urgent steps to exert his control over the quarrelsome Congress (I) party which had been held together by the force of Indira Gandhi's personality and political skills.

Some members of the party are quietly taking issue with the way in which Mr. Gandhi was sworn in as premier. Under the Constitution, the President selects a caretaker prime minister in the event of the incumbent's death until the majority parliamentary party in full caucus elects a new leader. There was no such caucus on Wednesday, and President Zail Singh swore in Mr. Gandhi as prime minister, not as a caretaker prime minister.

One of the failings of Indian democracy is that it has never spawned a credible, effective, or national opposition. This is due in part to the force of the personality of Rajiv's mother and of his grandfather.

Yet opposition leaders have recently begun to move tentatively toward a joint electoral strategy. They have already protested the manner in which Mr. Gandhi was hastily sworn in. It can be assumed that they will also take issue with the very concept of a dynastic heir.

Buffeted by the growing regional strains and by a political process whose rules he disdains, Rajiv Gandhi will have to decide soon whether to hold parliamentary elections on schedule in January, or defer them to June.

Many political analysts are convinced he will hold elections on schedule. His mother's assassination, at a time when the party's fortunes were discernibly beginning to flag, could well reverse what has been a downward trend since 1982. His own prestige would be enhanced enormously with a sweeping electoral victory.

A sympathy vote would be a compelling factor, which could assist and actually strengthen Indian unity.