Tekashi69's remarkable “rags to snitches” story took another turn Friday, with the release of a new music video shot while on home confinement.

Tekashi just streamed from in-home incarceration, setting an Instagram Live record with 2 million people tuning in. 6ix9ine trolled off the bat, bumping "Bad Boys" while toying with a pair of handcuffs. Tekashi got a lot off his plate ... admitting…