Yo Gotti, Roc Nation Demand Changes in Deadly Mississippi Prisons

Yo Gotti's sick and tired of the fatal bloodshed in Mississippi State Prisons, so he's enlisted Jay-Z's Roc Nation to demand the Governor make immediate changes ... or face a lawsuit.

On the heels of 5 inmates getting killed in 3 different MS prisons ... Gotti's called on Team Roc -- the philanthropic arm of Roc Nation -- and it fired off a letter Thursday to Gov. Phil Bryant. In the letter, they make it clear they'll take legal action if Bryant doesn't take steps to improve prison conditions.

Gotti's pissed off because 2 of the deaths went down at the prison known as Parchman Farm ... not far from his hometown of Memphis. Gotti says the prison conditions are "absolutely inhumane and unconstitutional."

Prison violence in Mississippi has increased sharply in the last 10 days, with riots and escapes. Critics say gangs have almost literally taken over some of the penitentiaries ... which are reportedly woefully understaffed and underfunded.

In its letter to the Governor, Team Roc says inmates -- male and female -- are "forced to live in squalor, with rats that crawl over them as they sleep on the floor, having been denied even a mattress for a cot." They believe the conditions are so bad, they constitute cruel and unusual punishment ... a violation of the Eighth Amendment.