Nick Reiner 'Calm but in a fog' days after Rob and Michele Reiner murders

Nick Reiner is spending his days in an L.A. jail, dealing with the aftermath of the violent murders of his parents, and he's not been able to fully process it ... TMZ has learned. A source with direct knowledge tells TMZ ... Nick is not reeling in grief. Rather, he's "in a fog"  ... in no small part due to his medical condition and the meds he's ta...