The Indian Army now patrolling many of this country's cities is a tough, formidable force that prompts fear and respect among the population, according to security experts here, who say it is the government's best hope for containing the violence that erupted after the assassination of prime minister Indira Gandhi.

Ordering elements of India's 1.1 million-man Army into the streets was necessary, the experts say, because police, who are closer to the population, were not acting firmly enough to quell the wave of violent reprisals by Hindus against the minority Sikh population in several places.

Gandhi was gunned down on Wednesday by two of her personal bodyguards, both of whom were identified as Sikhs.

But the assassination also has sharply dramatized a growing internal issue within the Army -- what to do about the large proportion of Sikh fighting men and officers in the ranks.

Although Sikhs account for only about 2 percent -- about 15 million people -- of India's 717 million population, they make up 10 to 12 percent of the Army, or the equivalent of 100,000 to 120,000 troops. In addition, at least 20 percent of the officer corps are Sikhs.

With a long and proud tradition as warriors, the Sikhs are widely viewed as among the best and most loyal soldiers in the world.

Yet, as militants in the Sikh majority in the northern state of Punjab have pressed harder in recent months for an independent state, and as Sikh-Hindu violence has spread, the situation has accelerated strains within the military.

In June, several hundred Sikh soldiers deserted their units and others killed a top Indian Army commander in reprisal for the Indian Army's assault on the Golden Temple in Amritsar, the Sikhs' holiest shrine, where Sikh terrorists were carrying out a campaign of violence against Hindus and moderate Sikhs.

Defense sources here said they expect that, as a consequence of events, the percentage of Sikhs in the Army will be allowed to drop and that the traditional extra effort to enlist them will ease. Some analysts say this is not necessarily a bad thing because it will make the Army a more representative national force.

There are also reports that the government is thinking about breaking up the ethnic regiments in which Sikhs, like the also highly praised Gurkha units, are concentrated, and then spreading the troops throughout the Army.

Today, the normally reliable conservative newspaper, The Statesman, reported, citing no sources, that one of the accomplices wounded in the Gandhi assassination is said to have told his doctors that a Sikh major general in the Army masterminded the assassination.

The Indian Defense Ministry quickly called the story "totally baseless and malicious." Defense specialists here also note that not much has been done thus far to try to bridge the gap between moderate Sikhs and the majority Hindus and this, too, can have an effect on relations within the services.

For the Army overall, the attack on the Golden Temple, which was highly controversial and exposed Army weaknesses in not using sophisticated assault techniques against what amounted to a well-armed terrorist army inside, nevertheless fortified the Army image of not flinching in carrying out an attack in the face of heavy losses and certain controversy.

That image is the key factor behind the government's action yesterday in ordering troops to assist civilian authorities where necessary in the streets.

While people sometimes do not take the Indian police seriously, "They know to stay away from the Army," one expert here said. "They are the ultimate trump card. They are not trigger-happy but there is a touch of ruthlessness" in the sense that people know "they are determined to do their job and they have the hardware," he said.

Although the Army's secondary mission is internal security, "They don't like it," added another specialist. "It distracts from their primary role of protecting the country's borders. They are soldiers trained to attack an enemy force rather than trained in the niceties of dealing with civil unrest. So they are apt to be more quick, violent and effective" than the police, and "that jolts" the population.

They are, in fact, being used more and more.

The inability or unwillingness of the local police to quell the initial violence is viewed by some as a way to allow some Hindu vengeance in the face of the assassination. But others say it is also in part because it is dangerous for police to try to thwart every action in situations in which they could easily be overcome by angry mobs.

As Gandhi's Saturday funeral approaches, the full dimensions of India's very large security forces are expected to come into play.

Aside from the Army and local police forces, India has about 90,000 men in a Central Reserve police force trained in riot control.

Another 80,000 men are in the border security force that is meant primarily as a buffer between the Indian and Pakistani armies.

Not all of these forces are along the border, however, and they are mobile, rather heavily armed and, like the Central Reserve police, available to the home minister in a civil crisis.

There is also a 10,000-man Indo- Tibetan border force that also is trained in antiterrorist activities. One member helped to gun down Gandhi's assassins.

So, sources say, there is a huge amount of police and paramilitary forces available to the government, with the Army used only in extreme emergencies such as the Golden Temple assault, the very serious Hindu-Moslem riots this spring around Bombay, and now the Gandhi assassination aftermath.

Other sources say that elements of four Army divisions, although not the entire divisions, have been spotted around New Delhi in recent days.

The Army also has been assigned the task of managing Saturday's funeral procession and handling crowd control and communictions, sources said. About 4,000 troops will line the processional route.

About two-thirds of the Army's 32 divisions remain along the borders with Pakistan and China.

This leaves about one-third for mobile duty around the country if necessary, and it is these forces that were used in combating the recent and severe internal unrest.

Still, some experienced Indian specialists say that if violence ever got out of hand, the Army could not control it.

"The country is just too big. Tomorrow, at the funeral, there will be 1 million to 1 1/2 million people. You can't really control that," one said.

The hypothetical possibility that India's Army might attempt to take control of the government at some point is viewed as highly doubtful, contrary to the apolitical traditions of a largely British-trained senior officer corps.

One experienced observer said there is not yet any likelihood of that happening.

But if, in the wake of the assassination and in the absence of another leader of Indira Gandhi's stature, the government over many months became immobilized by political unrest or indecision, then it is conceivable that there could be some Army "rescue" moves if it were perceived that the country was becoming vulnerable to its enemies, the observer said.

But one specialist who agreed to be quoted by name, K. Subrahmanyam of the Institute of Defense Studies and Analyses, rejects this theory.

"This very large explosion itself," he said of the assassination and its aftermath, "signals that the country can only be ruled by political consensus, and the Army understands that," he said.

They also understand, he said, that taking over a huge, developing country in the process of major industrialization "is not a simple thing."

India's is the world's fourth-largest Army, he said, and it cannot be compared to armies of less developed nations where the military frequently rules, the leadership corps is drawn from a narrow base and where there are no long traditions of keeping out of political activity.