The stage is set for the rough-and-tumblest, topsy-turviest, tit-for-tattiest television season ever, and if the programs on the air don't amuse the nation, the turmoil and strife behind the scenes just might.

There are two indisputably exciting things about the TV season now about to begin: ABC's "Battlestar Galactica" and NBC's Battlestar Silverman. The spectacular and refreshingly zippy scifi fantasy will probably be the most watched new series on the air. But in and near the TV industry, third-ranked NBC will ironically be the network that most people are keeping their eyes on.

That is simply and purely because of its new president and chief executive officer, Fred Silverman, who seems to have convinced friends, and foes that NBC is going to take off like a rocket with him at the controls. At the West Coast offices of what amounts to the NBC Freddievision Network in Burbank, Calif., morale is soaring and production bubbling, even though the network lumbered through last season to a lowly last place finish.

The same esprit de corporation reportedly prevails at NBC's New York headquarters in Rockefeller Center, as well. "Probably for the first time ever," says NBC Executive Vice President M.S. Rukeyser Jr., "the pace in television is being set by the No. 3 network."

Silverman has been suspiciously pokey about making the standard "team effort" disclaimer as the legends about his allegedly uncontainable genius escalate. In fact, NBC has not only the most illustrious leader but the most impressive top-management coven in network TV. This round table includes blunt and burly Irwin Segelstein, Silverman's right-hand man and longtime chum, and the only major network executive who could possibly qualify as a wit, redoutable and undoubting Paul L. Klein, who is the greatest authority on television Paul L. Klein has ever met.

Compared to this ensemble, the ABC crowds looks like square-jawed CPAs and the CBS crew a faceless and colorless committee.

In Hollywood, however, "Freddie" is the rallying cry. Freddie the Avenger, Freddie the Conqueror, and Freddie the Frontloader, who has already stacked the opening weeks of NBC's season with movies, specials and splashy acts designed to lure a big audience early.

Things had become a tad sluggish around old NBC, which in certain key ways had come to resemble such dolorous bureaucracies as the federal government - though not to that extreme, of couse. Hollywood producers say Silverman has wrought reform.

"There's a helluva lot of enthusiasm and a new sense of direction over there," says "Police Story" producer David Gerber, now preparing at least four new police shows starring David Casidy for airing on NBC this season. "Yes, I've worked with Freddie in the past. I've got the scars to prove it. He's mercurial, tough and demanding, but I'll say this for the s.o.b. - when he gets a show he likes, he really gives it a shot.

"NBC's chances are very good and I'll tell you why. Certainly ABC has a very strong schedule. But in television you're always stuck with committee decision. There hasn't been a strong man running a network since (James T.) Aubrey (of CBS) until Freddie. And he far surpasses even Aubrey. You'd have to do back to the early days of (William S.) Paley for comparison."

Silverman is known as the definitive tireless toiler. At the other networks, they say this can drive employes right to the executive washroom. But Gerber says the bravado is infectious and contagious. "You used to be lucky if you called NBC at 5:15 and anybody was still there to answer the phone," he says. "Now people are working Saturdays, Sundays, holidays. I've never seen anybody work so hard."

Ed Friendly, currently producing eight (perhaps nine) hours of a mini-series called "Backstairs at the White House" for airing on NBC after January, was an NBC vice president himself until he left 11 years ago to become an independent producer. "I've always had great affection for NBC," he says. "They're a great bunch of people over there. But I don't think they've ever had a whirlwind like this. I mean, he's all over the place'"

Do NBC's chances look good? "They certainly don't look bad," says Friendly. "But Freddie - I mean, Fred, he doesn't like to be called Freddie - I don't think you'll see any of his shows until mid-season."

Indeed, about all Silverman could do with the NBC fall schedule is move already-purchased programs around like hotels on a Monopoly board, plus arrange such gimmicky specials - called "stunts" in the trade - as a 25th-anniversary salute to Walt Disney's television programs and the first full-length telecast of "Dumbo," which will have the "Rocky" like task of going up against ABC's "Galactica."

Rukeyser boasts that NBC now has no less than 30 new pilots in development to replace possible faltering shows in the schedule so that "for January, we will have more to choose from than any network ever has." Competitors say this merely proves how little faith Silverman has in the fall schedule and how desperately he is trying to convince stockholders of the parent RCA Corp. that network prosperity is just around the corner even if it's not yet beating the door down.

NBC has added about 30 people to its program development department in Burbank - "middle echelon" types. Rukeyser says - increasing the population so heavily that the entire publicity staff had to be moved outside into trailers surrounded by a wire fence. Since the trailers look a little like a parked train, NBC publicist Gene Walsh named the compound "The Silverman Express."

Michael Shamberg, a young independent producer who's just sold the network on financing his 2-year-old "Gossip" sit-com, says the vibes at NBC are the best in town. "Every department has new people in it, and they're young and aggressive and they try to stir up new ideas," he says.

Shamberg says the new zest is because of Silverman, but in a nearly metaphysical way. "The power to get things done is such an illusion. After Freddie left ABC and before he came to NBC, NBC was in kind of a holding pattern. Everybody was saying, 'Silverman may be able to do it, and he may not.'

"But once he came in, the newtork suddenly had confidence. Everybody had confidence. And the illusion of confidence tends to get things going.

"Freddie Silverman coming to NBC is the most significant thing to happen in commercial television since - well, since whatever. Because there's a mandate for change. When somebody who has no reputation for change tries to make changes, they don't have a chance, but somebody like Freddie can do what he wants and people will pay attention."

The hopeful signs are not only for RCA stockholders or the lunchtime gangs in the NBC commissaries. Because Silverman has promised that what he's after at NBC is what Rukeyser calls "success with honor" - ratings dominance built on something more substantial and valuable than the punk comedies and sex larks Silverman installed at ABC.

If Silverman established the fact that you can be No. 1 and still program "quality" material - and the word "quality" trips more readily from a broadcaster's tongue even then the word "profits" - he will have contributed incalculably to the betterment of television and, inevitably, of the American way of life that is largely built around it.

In a sense, it may be incumbent upon Silverman to do what many feel President Carter has failed to do - provide dynamic direction for a vast bureaucracy and even instill new moral leadership. Silverman has a persuasively lofty side that goes beyond ratings, fourth-quarter earnings and costs-per-thousand ad rates.

So he may told out more hope, at this point, for the national well-being than President Carter does, and Silverman's struggle to achieve what he wants may make a substantial more rivetting real-life mini-series.

Mort Lachman, executive producer of "All in the Family" at Norman Lear's Tandem Productions, has followed Silverman's career at all three networks. Though Silverman has not left a trail of artistic triumphs behind has faith that the great man will emerge from inside the great programmer.

"CBS is what Freddie Silverman was," says Lachman. "ABC is what he is. And NBC - that's what Freddie Silverman hopes to be."