Nine months after he was jailed on a welter of racketeering charges, John A. "Junior" Gotti, the son of the Gambino crime family boss, walked out the front door of the federal courthouse here as a theoretically free man, but one who will have to spend the months until and during his trial under strict house arrest.Bouncing down the courthouse steps, Gotti, 34, forced his way past cameras, walked into a bear hug from his brother-in-law, Carmine Agnello, and then slipped into a white Mercedes driven by his sister, Victoria. He was driven to his $700,000 home in Oyster Bay on Long Island where his wife and four children held a party.

Gotti's release on bail came after two grueling weeks of negotiations between his lawyers and federal prosecutors. Although two dozen of Gotti's relatives and friends posted $10 million worth of homes and businesses as collateral for his bail, prosecutors subjected them to intense scrutiny to make certain that none were bought with criminal earnings.

Under conditions negotiated between the government and defense lawyers, Gotti will be confined to his house around the clock. He will have to wear an electronic ankle bracelet that tracks his movements and will only be able to see visitors on an approved list. His calls will be monitored and a security guard he must pay for will be posted outside his house at all hours.

Gotti has been accused of extorting payments from the Scores strip club in Manhattan and defrauding people who bought prepaid telephone cards, charges that could result in a maximum sentence of 20 years in prison. His father, John Gotti, 58, is spending a life sentence in a federal penitentiary in Illinois on charges of murder. He recently had surgery for throat can-cer.

Gotti's trial is scheduled for early January.