About the lineage of the 17 Tantras.
"In Tibet, the ones who made this Nyingtik teaching of Clear Light spread were the great masters who possessed their special direct transmission, chiefly the great pandita Vimalamitra, and Guru Padmasambhava. In the room known as Utseʼ Barkhang in Samye, Vimalamitra gave the cycle of the Innermost Secret Nyingtik of Dzogpachenpo in strictest secrecy to five disciples: the King Trisong Detsen, Nyangben Tingdzin Zangpo, Prince Muni Tsepo, Kawa Platsek and Chokro Luyi Gyaltsen. The tradition of Nyingtik which came down from this transmission is known as the Vima Nyingtik. The Vima Nyingtik itself can be categorized into tantras, agamas, and upadeshas, which are all taught within it. The tantras here refer to the Seventeen Tantras of the pith instruction. The agamas found in the Vima Nyingtik are the golden lettered instructions, the turquoise lettered instructions, the copper lettered instructions, and the conch lettered instructions. These are what are called the ʻfour volumes of profound instructionsʼ. Then the upadeshas refer to the 119 treatises of essential pith instructions. Vimalamitra spent thirteen years in Tibet, and then promising to return to Tibet every hundred years as an emanation to further the Clear Light teaching of Dzogpachenpo, he left for the Wutaishan mountain in China. There he remain until all of the 1000 buddhas of this Fortunate Kalpa have appeared. When they have all done so, he will once again go to Vajrasana in India, where he will manifest the state of complete and perfect enlightenment.
Fifty-five years after Vimalamitraʼs departure for Wutaishan, Nyangben Tingdzin Zangpo, having given the transmission of the Vima Nyingtik cycle to Be Lodro Wangchuk, attained the rainbow body. Be Lodro Wangchuk gave the pith instructions cycle of Nyingtik to Dangma Lhundrup Gyaltsen, who in turn passed it on to Chetsun Senge Wangchuk. He transmitted it to Gyalwa Shyangton Tashi Dorje, and then left this world in a rainbow body. Gyalwa Shyangton passed it on to the great siddha Khepa Nyimabum, who gave the teachings to his principal disciple Guru Jober. Then Guru Jober transmitted them to Trulshik Senge Gyabpa. He in turn gave them to the great siddha Drupchen Melong Dorje, who passed them on to the vidyadhara Kumaradza. Kumaradza gave the teachings to the Omniscient Longchen Rabjam, and so this is how the lineage flowed down to the Omniscient Longchenpa, who was born in the year 1308."http://www.knamdrol.org/nyingthig-transmissions.pdf