TMZ obtained this video of the man outside the public service Thursday evening in NYC. A large crowd gathered outside the Frank E. Campbell "Funeral Chapel" immediately following the service, and cops say the suspect was blocking pedestrians.

A dozen cops were on the scene when police told him to move to the other side of the street ... and that's when things got heated. First, a shouting match between the man and an officer -- and then a full-fledged fight when cops tried to take him into custody.

In the end, NYPD arrested the guy for resisting arrest, obstruction and disorderly conduct.

The service went off without a hitch inside. As we reported ... LL Cool J, Remy Ma and Ice-T were among the celebs who showed up to pay their last respects to the Mobb Deep rapper.