my plated lizard lost his tail

Question
will his tail grow back or is he goig to die help

Answer
 That would depend on how he lost it.  Many species of lizard, when feeling threatened, will "drop" a portion of their tail to distract the predator and escape. Those that drop the tail will grow them back, but not as nice as the original.  If the tail was lost through trauma, a vet visit would be a good idea to make sure the stump is free from infection or danger of gangrene.