I really can't say much about the storyline of the show without giving spoilers away. But I'll try to explain the premise of the show. Raymond Reddington, played by James Spader, is a criminal mastermind, a kingpin of the highest degree, who also happens to be on FBI's Most Wanted List. He turns himself in and agrees to give valuable information on several other criminals(straight up snitching, if you ask me), just like him. This, in exchange for immunity from all the crimes he has committed/or is accused of.
Try the first season or two and just see if you like it bro