The Witness Protection Program was established in 1970. The hearings were held ca. 1959-60. Cicci certainly would have gotten immunity to testify. After the hearings, he'd either be released to "go into the wind" on his own, or be sent to a prison in some secure and (relatively) comfortable wing or suite, as was Joe Valachi. He would have been dead real quick in general population but he could have survived, as Valachi did, in more secure surroundings. He, at least, stuck to his agreement with the Feds, and testified as he was supposed to. Maybe the Feds felt an obligation to protect him going forward. But, as dt said, he was of limited use to the Feds, and they might not have made any special efforts to protect him in prison. Sammy Da Bull Gravano, by contrast, probably got better protection in prison than the President gets in Washington--precisely because he was very useful to the Feds in ratting out other mobsters.

This leads to another interesting question: what would have happened to Pentangeli if he hadn't decided to kill himself? After breaking his agreement with the Feds on national TV (and thus embarrassing the FBI and the Senate), he'd have totally blown his credibility. He'd have been of absolutely no use to the Feds or anyone else in the law enforcement/political chain. So, there's no guarantee--in fact, no reason--that the government would have kept him in that pool-table-equipped suite on an Air Force base. I'm gussing that, eventually, they would have put him in prison, and not necessarily in a secure cell or wing.